If there is a delay when testing,setting,clearing flags it is VERY short. I know this because I have used flags in some pretty extensive ways.

Since you can't assign a string or number value to a variable (yet, I hope) if you want to have several flag possibilities, you have to CLEAR all the relative flags before setting a flag. I have macros that literally clear 40 or 50 flags, and then set one. And I haven't noticed anything other than a slight hiccup in the speed of the macro.