Do you think it is OK to start PBF at the mastery level, even if I can't do the required number of repetitions but I can perform the movements?

For example, I can do a full pullup, but only about 5 or 6. If I did this for my assessment, it would put me at the 1 leg chair assisted pull up level.

I think I'd rather do the full movements, and increase my reps as I get stronger. Can anyone see any problems with this?