Why Are Some Keys Hard-coded into Mods?

Why is it that some keys are hard-coded and not bindable in either the menu or some kind of config file? By hard-coded keys I refer to things like in Project X (A masterpiece in my opinion!) the M and R keys are mapped to the Map and Reload functions respectively. I would like to remap them but there is no way to do this. This seems to be the way of all mods I've tried with extra keys. Is this just a limitation of the original source code or something?

@Per-Scan wrote:Why is it that some keys are hard-coded and not bindable in either the menu or some kind of config file? By hard-coded keys I refer to things like in Project X (A masterpiece in my opinion!) the M and R keys are mapped to the Map and Reload functions respectively. I would like to remap them but there is no way to do this. This seems to be the way of all mods I've tried with extra keys. Is this just a limitation of the original source code or something?

Now that I think of it, I think you're right. Anybody else notice this? I remember Project X and Spear of Dreams having extra buttons, non of which are mappable.

I think Eisenfaust Origins should be on that list too. The secret weapon you get has an alternate firing button which is X instead of your desired primary firing button.

@WolferCooker wrote:I think Eisenfaust Origins should be on that list too. The secret weapon you get has an alternate firing button which is X instead of your desired primary firing button.

I never got the weapon so I forgot about it. I did get a few levels unlocked though.