I am not sure that most matches have enough deuces to worry about it, but I could be wrong... I doubt the majority of matches, at any level, have more than 5 deuces in one game...
I play in some USTA leagues here. The singles in no ad, which I hate to play... And they of coarse we play a 9 point tie-breaker which menas the first person to 5 by 1. At 4-4 it is sudden death all the way... I have been there, lost one, won one... No fun...
As far as capping deuces, I do nto mind that as much. The doubles Thursday night league I play in does that, 3 tops and then a sudden death point... I would personally rather play it out, but if the game was going to change and I had to pick one or the other I would pick this one hands down!