There is no way to do that for the sequence editor. Of course, in an operator interface, you can edit the source code to provide any menu items you like with exactly the shortcut keys you want.
If you want to make the shortcut keys in an OI vary according to the selected process model, your OI could read a sequence specified shortcut key value from a entry point sequence local variable that has a specific name you designate. You could then place instances of that local variable in the process model entry point sequences for which you want to specify shortcut keys.