As of the morning of May 2 with full updated standalone libraries, PitBull r34248 (with PitBull_BarFader, PitBull_EstimatedHeals,PitBull_RangeCheck updated here morning of May 2) along with PitBull_CombatFader r34114, a single major problem. With either a hunter/warlock pet frame for your character (not in a party) or the target of target frame (only when the target of target is you and the target is a party member), the two frames "blink" distractingly rapidly when out of combat. When PitBull_CombatFader is disabled in options for those two frames, the blinking stops. Did not experience the inappropriate blinking with either the player, party or target frames (only other ones tested).
For example, summon your pet when not in a party. Don't go into combat (i.e. you are in a city). Very soon after summoning, the pet frame will "blink" between 25% (or whatever you have it set to) outAlpha and 100% (or whatever you have it set to) inAlpha very rapidly. Sometimes the blinking stops when moving around, but most of the time it happens. This also occurs if you log on with the pet already summoned.
Identical thing happens when you (as a non-hunter/warlock character) are in a party, you have a (non-hunter/warlock) party member targeted and they have you targeted. Again, out of combat (was in a city). Your frame--as target of target--blinks distractingly rapidly between the full & in-combat alpha values.
Had to disable PitBull_CombatFader completely because of this inappropriate blinking.
EDIT: this is still occurring with the later PitBull r34336 (PitBull_CombatFader is unchanged as of this date from r34114). It is also occurring in combat with the target of target frame. As above, the problem ends when you go into the PitBull Options & disable CombatFader for the affected frame (or you disable it completely before logging on).