Question about Add on Aircraft

I have a question.
Do simulator software developers use the default key assignments in FS2K2
(or any sim for that matter that their aircraft is designed to be used
in)....when they design an add on aircraft to be used in that simulator?
Reason I ask is this. Can changing the default key assignments to another
key....say the idle cutoff from cntrl/shift/F1 to say...cntrl/q for example,
foul up an installation of an add on aircraft? Keep in mind I'm not talking
about controller button assignments. That doesn't change the default key
that function is assigned to in the simulator. I'm just talking about
changing key assignments only and asking if changing them might cause
conflicts with add on aircraft!!!
Thanks.
Dudley