diff --git a/Tools/autotest/rover.py b/Tools/autotest/rover.py
index 20ab334a732ba5..43d7f5bcf20fe9 100644
--- a/Tools/autotest/rover.py
+++ b/Tools/autotest/rover.py
@@ -6200,7 +6200,7 @@ def printmessage(mav, m):
 
         # ensure setting the private channel mask doesn't cause us to
         # execute these commands:
-        self.set_parameter("SERIAL2_OPTIONS", 1024)
+        self.set_parameter("MAV3_OPTIONS", 2)
         self.reboot_sitl()  # mavlink-private is reboot-required
         mav2 = mavutil.mavlink_connection("tcp:localhost:5763",
                                           robust_parsing=True,
diff --git a/Tools/autotest/test_param_upgrade.py b/Tools/autotest/test_param_upgrade.py
index 5e353a70bc2bc8..39f9c22b349991 100755
--- a/Tools/autotest/test_param_upgrade.py
+++ b/Tools/autotest/test_param_upgrade.py
@@ -5,6 +5,9 @@
 
 ./Tools/autotest/test_param_upgrade.py --vehicle=arduplane --param "GPS_TYPE=17->GPS1_TYPE=17" --param "GPS_TYPE2=37->GPS2_TYPE=37" --param "GPS_GNSS_MODE=21->GPS1_GNSS_MODE=21" --param "GPS_GNSS_MODE2=45->GPS2_GNSS_MODE=45" --param "GPS_RATE_MS=186->GPS1_RATE_MS=186" --param "GPS_RATE_MS2=123->GPS2_RATE_MS=123" --param "GPS_POS1_X=3.75->GPS1_POS_X=3.75" --param "GPS_POS2_X=6.9->GPS2_POS_X=6.9"  --param "GPS_POS1_Y=2.75->GPS1_POS_Y=2.75" --param "GPS_POS2_Y=5.9->GPS2_POS_Y=5.9"  --param "GPS_POS1_Z=12.1->GPS1_POS_Z=12.1" --param "GPS_POS2_Z=-6.9->GPS2_POS_Z=-6.9" --param "GPS_DELAY_MS=987->GPS1_DELAY_MS=987" --param "GPS_DELAY_MS2=2345->GPS2_DELAY_MS=2345" --param "GPS_COM_PORT=19->GPS1_COM_PORT=19" --param "GPS_COM_PORT2=100->GPS2_COM_PORT=100" --param "GPS_CAN_NODEID1=109->GPS1_CAN_NODEID=109" --param "GPS_CAN_NODEID2=102->GPS2_CAN_NODEID=102" --param "GPS1_CAN_OVRIDE=34->GPS1_CAN_OVRIDE=34" --param "GPS2_CAN_OVRIDE=67" --param "GPS_MB1_TYPE=1->GPS1_MB_TYPE=1" --param "GPS_MB1_OFS_X=3.14->GPS1_MB_OFS_X=3.14"  --param "GPS_MB1_OFS_Y=2.18->GPS1_MB_OFS_Y=2.18"  --param "GPS_MB1_OFS_Z=17.6->GPS1_MB_OFS_Z=17.6"  --param "GPS_MB2_TYPE=13->GPS2_MB_TYPE=13" --param "GPS_MB2_OFS_X=17.14->GPS2_MB_OFS_X=17.14"  --param "GPS_MB2_OFS_Y=12.18->GPS2_MB_OFS_Y=12.18"  --param "GPS_MB2_OFS_Z=27.6->GPS2_MB_OFS_Z=27.6"  # noqa
 
+./Tools/autotest/test_param_upgrade.py --vehicle=arduplane --param "SERIAL1_OPTIONS=1024->MAV2_OPTIONS=2" --param "SERIAL2_OPTIONS=4096->MAV3_OPTIONS=4"
+./Tools/autotest/test_param_upgrade.py --vehicle=arduplane --param "SERIAL1_OPTIONS=5120->MAV2_OPTIONS=6"
+
 AP_FLAKE8_CLEAN
 '''
 
diff --git a/libraries/AP_HAL/UARTDriver.h b/libraries/AP_HAL/UARTDriver.h
index 6428080e587160..91134d4828861f 100644
--- a/libraries/AP_HAL/UARTDriver.h
+++ b/libraries/AP_HAL/UARTDriver.h
@@ -86,7 +86,7 @@ class AP_HAL::UARTDriver : public AP_HAL::BetterStream {
     virtual bool set_options(uint16_t options) { _last_options = options; return options==0; }
     virtual uint16_t get_options(void) const { return _last_options; }
 
-    enum {
+    enum Option {
         OPTION_RXINV              = (1U<<0),  // invert RX line
         OPTION_TXINV              = (1U<<1),  // invert TX line
         OPTION_HDPLEX             = (1U<<2), // half-duplex (one-wire) mode
@@ -97,11 +97,16 @@ class AP_HAL::UARTDriver : public AP_HAL::BetterStream {
         OPTION_PULLUP_TX          = (1U<<7), // apply pullup to TX
         OPTION_NODMA_RX           = (1U<<8), // don't use DMA for RX
         OPTION_NODMA_TX           = (1U<<9), // don't use DMA for TX
-        OPTION_MAVLINK_NO_FORWARD = (1U<<10), // don't forward MAVLink data to or from this device
+        OPTION_MAVLINK_NO_FORWARD_old = (1U<<10), // // moved to GCS_MAVLINK::Option
         OPTION_NOFIFO             = (1U<<11), // disable hardware FIFO
-        OPTION_NOSTREAMOVERRIDE   = (1U<<12), // don't allow GCS to override streamrates
+        OPTION_NOSTREAMOVERRIDE_old   = (1U<<12), // moved to GCS_MAVLINK::Option
     };
 
+    bool option_is_set(Option option) const {
+        return (_last_options & (uint16_t)option) != 0;
+    }
+
+
     enum flow_control {
         FLOW_CONTROL_DISABLE=0,
         FLOW_CONTROL_ENABLE=1,
diff --git a/libraries/AP_SerialManager/AP_SerialManager.cpp b/libraries/AP_SerialManager/AP_SerialManager.cpp
index 358fe717e353c7..1811a54aad7d5c 100644
--- a/libraries/AP_SerialManager/AP_SerialManager.cpp
+++ b/libraries/AP_SerialManager/AP_SerialManager.cpp
@@ -272,8 +272,8 @@ const AP_Param::GroupInfo AP_SerialManager::var_info[] = {
 #if HAL_HAVE_SERIAL1_PARAMS
     // @Param: 1_OPTIONS
     // @DisplayName: Telem1 options
-    // @Description: Control over UART options. The InvertRX option controls invert of the receive pin. The InvertTX option controls invert of the transmit pin. The HalfDuplex option controls half-duplex (onewire) mode, where both transmit and receive is done on the transmit wire. The Swap option allows the RX and TX pins to be swapped on STM32F7 based boards.
-    // @Bitmask: 0:InvertRX, 1:InvertTX, 2:HalfDuplex, 3:SwapTXRX, 4: RX_PullDown, 5: RX_PullUp, 6: TX_PullDown, 7: TX_PullUp, 8: RX_NoDMA, 9: TX_NoDMA, 10: Don't forward mavlink to/from, 11: DisableFIFO, 12: Ignore Streamrate
+    // @Description: Control over UART options. The InvertRX option controls invert of the receive pin. The InvertTX option controls invert of the transmit pin. The HalfDuplex option controls half-duplex (onewire) mode, where both transmit and receive is done on the transmit wire. The Swap option allows the RX and TX pins to be swapped on STM32F7 based boards.  NOTE that two bits have moved from this parameter into MAVn_OPTIONS!
+    // @Bitmask: 0:InvertRX, 1:InvertTX, 2:HalfDuplex, 3:SwapTXRX, 4: RX_PullDown, 5: RX_PullUp, 6: TX_PullDown, 7: TX_PullUp, 8: RX_NoDMA, 9: TX_NoDMA, 10: UNUSED OPTION (was Don't forward mavlink to/from); see MAVn_OPTIONS, 11: DisableFIFO, 12: UNUSED OTION (was Ignore Streamrate); see MAVn_OPTIONS
     // @User: Advanced
     // @RebootRequired: True
     AP_GROUPINFO("1_OPTIONS",  14, AP_SerialManager, state[1].options, DEFAULT_SERIAL1_OPTIONS),
diff --git a/libraries/GCS_MAVLink/GCS.h b/libraries/GCS_MAVLink/GCS.h
index efcc3398e3bfd8..ca7d4c3f1cc99f 100644
--- a/libraries/GCS_MAVLink/GCS.h
+++ b/libraries/GCS_MAVLink/GCS.h
@@ -516,6 +516,23 @@ class GCS_MAVLINK
     virtual bool persist_streamrates() const { return false; }
     void handle_request_data_stream(const mavlink_message_t &msg);
 
+    AP_Int16 options;
+    enum class Option : uint16_t {
+        // first bit is reserved for: MAVLINK2_SIGNING_DISABLED = (1U << 0),
+        NO_FORWARD                = (1U << 1),  // don't forward MAVLink data to or from this device
+        NOSTREAMOVERRIDE          = (1U << 2),  // ignore REQUEST_DATA_STREAM messages (eg. from GCSs)
+    };
+    bool option_enabled(Option option) const {
+        return options & static_cast<uint16_t>(option);
+    }
+    void enable_option(Option option) {
+        options.set_and_save(static_cast<uint16_t>(options) | static_cast<uint16_t>(option));
+    }
+    void disable_option(Option option) {
+        options.set_and_save(static_cast<uint16_t>(options) & (~ static_cast<uint16_t>(option)));
+    }
+    AP_Int8 options_were_converted;
+
     virtual void handle_command_ack(const mavlink_message_t &msg);
     void handle_set_mode(const mavlink_message_t &msg);
     void handle_command_int(const mavlink_message_t &msg);
diff --git a/libraries/GCS_MAVLink/GCS_Common.cpp b/libraries/GCS_MAVLink/GCS_Common.cpp
index 8f3719a8208675..45fc776dcc8fda 100644
--- a/libraries/GCS_MAVLink/GCS_Common.cpp
+++ b/libraries/GCS_MAVLink/GCS_Common.cpp
@@ -152,11 +152,26 @@ bool GCS_MAVLINK::init(uint8_t instance)
         return false;
     }
 
+    // PARAMETER_CONVERSION - Added: May-2025 for ArduPilot-4.7
+    // convert parameters; we used to use bits in the UARTDriver to
+    // remember whether the mavlink connection on that interface was
+    // "private" or not, and whether to ignore streamrate sets via
+    // REQUEST_DATA_STREAM.  We moved that into the MAVn_OPTIONS, this
+    // is the conversion:
+    if (!options_were_converted) {
+        options_were_converted.set_and_save(1);
+        if (_port->option_is_set(AP_HAL::UARTDriver::Option::OPTION_MAVLINK_NO_FORWARD_old)) {
+            enable_option(Option::NO_FORWARD);
+        }
+        if (_port->option_is_set(AP_HAL::UARTDriver::Option::OPTION_NOSTREAMOVERRIDE_old)) {
+            enable_option(Option::NOSTREAMOVERRIDE);
+        }
+    }
+
     // and init the gcs instance
 
-    // whether this port is considered "private" is stored on the uart
-    // rather than in our own parameters:
-    if (uartstate->option_enabled(AP_HAL::UARTDriver::OPTION_MAVLINK_NO_FORWARD)) {
+    // whether this port is considered "private":
+    if (option_enabled(Option::NO_FORWARD)) {
         set_channel_private(chan);
     }
 
@@ -4417,10 +4432,12 @@ void GCS_MAVLINK::handle_message(const mavlink_message_t &msg)
 #endif
 
     case MAVLINK_MSG_ID_REQUEST_DATA_STREAM:
-        // only pass if override is not selected 
-        if (!(_port->get_options() & _port->OPTION_NOSTREAMOVERRIDE)) {
-            handle_request_data_stream(msg);
+        if (option_enabled(Option::NOSTREAMOVERRIDE)) {
+            // options indicate we are to ignore this stream rate
+            // request
+            break;
         }
+        handle_request_data_stream(msg);
         break;
 
     case MAVLINK_MSG_ID_DATA96:
diff --git a/libraries/GCS_MAVLink/GCS_MAVLink_Parameters.cpp b/libraries/GCS_MAVLink/GCS_MAVLink_Parameters.cpp
index 658f936a816e3d..dd259cb90b5340 100644
--- a/libraries/GCS_MAVLink/GCS_MAVLink_Parameters.cpp
+++ b/libraries/GCS_MAVLink/GCS_MAVLink_Parameters.cpp
@@ -202,6 +202,24 @@ const AP_Param::GroupInfo GCS_MAVLINK::var_info[] = {
     // @RebootRequired: True
     // @User: Advanced
     AP_GROUPINFO("_ADSB",   10, GCS_MAVLINK, streamRates[GCS_MAVLINK::STREAM_ADSB], DRATE(GCS_MAVLINK::STREAM_ADSB)),
+
+    // ------------
+    // IMPORTANT: Add new stream rates *before* the _OPTIONS parameter.
+    // ------------
+
+    // @Param: _OPTIONS
+    // @DisplayName: Bitmask for configuring this telemetry channel
+    // @Description: Bitmask for configuring this telemetry channel. For having effect on all channels, set the relevant mask in all MAVx_OPTIONS parameters. Keep in mind that part of the flags may require a reboot to take action.
+    // @RebootRequired: True
+    // @User: Standard
+    // @Bitmask: 1:Don't forward mavlink to/from, 2:Ignore Streamrate
+    AP_GROUPINFO("_OPTIONS",   20, GCS_MAVLINK, options, 0),
+
+    // PARAMETER_CONVERSION - Added: May-2025 for ArduPilot-4.7
+    // Hidden param used as a flag for param conversion
+    // This allows one time conversion while allowing user to flash between versions with and without converted params
+    AP_GROUPINFO_FLAGS("_OPTIONSCNV",   21, GCS_MAVLINK, options_were_converted, 0, AP_PARAM_FLAG_HIDDEN),
+
     AP_GROUPEND
 };
 #undef DRATE