Hard numbers are nice but don't rely on them. Go by feel. As you gain familiarity with an aircraft you'll be able to tell when to drop a notch of flaps without needing to look at your airspeed. That's MUCH more effective, especially when using flaps for maneuvering where timing is the key.
well said, and i do this alot in my F4U. i know first notch is about 250ish, if i dont hear the flap noise i reduce throttle till i "feel" im below 250.
Back to OP, I dont really have a time to use flaps, i just use them, to dump E in a scissor, get some extra lift in a vert, on a rope, in a loop, turn tighter circles, try for better angles, take off and landing on CV's.