You don't seem to understand the issue, so let me better explain.
Non-permanent surfaces accelerate their effects(including damage) in order to disappear faster. That means that outside of actual combat, you'll take 3-4 turns worth of 'standing in fire' damage(on top of also actually burning), in the time a single regeneration effect takes to activate.
You do not get to move all your dudes at once, and you do not get to decide when a fight is actually over, so unless both of those things happen, harmful surfaces should have a time/distance based cooldown on applying their effects equal to the rate at which once-per-turn effects such as regeneration healing occur.
That is to say: if a surface is meant to disappear faster after a fight, it should do so by having turns taken away from it's duration, rather than by having multiple turns in a single turn's timeframe.
