The only good soln is too not worry about it and replace when they get really bad or break. They are cheap enough and cvds just tend to pop out or bend on the Revo (esp if you get rpm arms.)
I have nitro revo diffs and have never blown one, ex the one I was trying to blow. The CD kit is a different story. I've killed at least two of them. Both are a horrible design tho and prone to leakage compared to their 1/8 counterparts. Diffing out on 500k fluid (which is literally thicker than molasses and at least as messy) is rediculous. TRX gaskets suck. More than anything I hate how hard they are to get to vs a 1/8th scale or Savage. A few screws on those and the diff pops out. On a Revo its major surgery and far more time consuming. I am nice to diffs just to not to have work on them.
Honestly, I can't see a Revo ever beating a good truggy driver with all else being equal. Most of the local tracks I see that have both classes have the MT (ie Revo class) TQ well into the middle of the pack of the truggy drivers.
I am not a big racer or a pro by any means, but
watching what some of the really good trug drivers at Barnstormers during the RCM Bash (and other times) can do with a truggy is simply amazing and far beyond what a Revo could hope to pull off. The best lap by a Revo was more than 5secs behind the best lap of the trug drivers (35s vs 41s.)
I'm not saying it can't be done, a Revo beating a truggy, but beyond a certain level of driving, the Revo just does not have the capability a truggy has.