The thing is C2 was done not to have a fixed 60 fps framerate, but a V-synced based framerate as far as I understand, however, I agree that lower fps that does not vary too much should not be a problem for the player (I will keep an eye on this discussion)
For collisions however, I woild think it can be possible to have a more precise way to check them, but it would be more costly (moving first the sprite to a certain distance based off it's size, then check, if no collisions, repeat until you are arrived). So it will not be really efficient, I also supporrt the idea of a fixable framerate (like every 1/30 seconds, recalculate the non trigger based logic then render on screen, but that may cause issues with triggers triggering between those simulated ticks)