Wow.. I'm gobsmacked that anyone would even manufacture such a brain-dead device..
Especially when you consider the evolution of the standard PC keyboard, due to the IBM/Microsoft alliance. Microsoft took the IBM Common User Access guidelines
on board, and over time, developed standardised uses for all 12 function keys
.. And given that pretty much all PCs are designed from the ground up to be used with MS Windows, it's beyond stupid that a manufacturer would abandon the standard.
Thankfully, that kind of abomination seems to be extremely rare. I don't think we ought to be concerned about it.
The ultimate solution would be a fully interactive keyboard mapping setup in the core and the setup screen, including a button to "reset to factory default". That works for everyone, on every platform, on every keyboard. A key press that does not exist on one platform is irrelevant in that case.
It would work by first choosing a command to map, then choosing a key to bind the action to.
Choosing a command to map would include the options "prime <equipment...>", "mode change <eqipment...>", and "activate <equipment...>", where the choice of equipment is a 2nd level menu screen where you get to select from the installed set of equipment. It would require some checks so that if a piece of equipment doesn't exist any more at the time it is reference it's just ignored while in flight.
This would give everybody the option to set up their prime/mode-set/activate to precisely how they like it.
A lesser solution would be just to add the shift-number-keys to the existing allowed activation, but I'd still prefer the option to either prime, change mode, or activate on a per device, per key setup.
Also, there could be a "lock settings" option so that you can't mistakenly change the mode of something you really don't want to change by mistake.