then if it changes to a different fps for a certain amount of time, then it disables it. so if your fps jumps, your record won't be deactivated, i've not known fps to jump or drop for longer than two seconds so it shouldn't be too hard to solve that problem.
and if your fps does drop that much for that length of time, then you probably won't be able to make records whether or not it's deactivated for you or not.