I suppose it is this file that controls what works in Python in the web simulator using ion.keydown: https://github.com/numworks/epsilon/blob/master/ion/src/simulator/shared/keyboard.cpp
Is this correct?

The simulator supports more keys when not using ion.keydown in Python: Tab (toolbox), Backspace, Enter (EXE), Shift, Alt+x (exp), Alt+v (var), Alt+e (EE), Alt+r (sqrt), Alt+p (pi), Alt+Shift+2 (**2), and the arrow keys. In Python using ion.keydown it only seems to support Tab, Enter, Shift, and the arrow keys.

I would prefer if all physical keys worked in all situations in the simulator. It would be better if there was a mapping so that all keys on the screen keyboard in the simulator could be pressed using physical keyboard keys that were easy to remember. E.g. Alt+s (sin), Alt+Shift+c (acos), Alt+n (x,n,t), Alt+a (Ans), etc.

An added advantage for teachers would be if the screen keyboard key was pressed when you press it on the physical keyboard. There would be a slight problem if you want to press '+' on a US keyboard, since you need to press Shift+=, but that would lead to that Shift key was pressed and status shift was lit, but that could be turned off as soon as '=' key was pressed, and then only the '+' key would be pressed on the screen keyboard.

Test using Anykeys:
https://my.numworks.com/python/mobluse/anykeys