I don't relax at the moment, but from what I've been reading (plus I relaxed my niece's hair with Motions(super)...),as long as you 'base' your scalp really well, you shouldn't burn at all.
welcome to the forum naturallyme. i think it really depends on the individual. some people have sensitive scalps. i can rec what was mild on my scalp but it may burn you like hell!!
i will say keep trying different relaxers and make a note each time you relax.
just remember that the relaxer is meant to be kept off the scalp, at least during application. and it should not burn if applied properly. hope this helps.