Until reading this thread it didn't hit me, but I noticed that when I ran lipo unregulated last weekend, I started to get hesitation and delays with my Futaba 2.4. The reciever didn't burn up but it acted funny like it never has before.
The ACE servos can be ran unregulated, I run the 1015's as do others with no regulator without any problems. 1313's should be the same, just call ACE Hobby Supply and ask them if you want a for sure answer, but they may tell you no just to be on the safe side and avoid warranty issues, but my track experience says they are fine.