Gmade came out with some piggy back shocks recently that actually look like they might work as intended. Adjustable pressure on the piggyback, and the spring should allow for some of that pressure to be absorbed instead of blowing out a shock bladder.
But I don't know how well these will function. As we all know the transition to small scale doesn't always work out. Lot of tiny little o-rings, more chance of leaking.
http://www.gmade.net/bbs/zboard.php?...desc=asc&no=28