I went last may and only got a wheel chair return time once, but I forget which ride it was. Basically, any ride that uses the FP entrance for HA, if the standby wait time is significantly longer than the FP wait time (say a half hour or more longer), you may get a return time in order to make your wait comparable. You get a paper form with a time written on it, and return after that time to go straight through the FP line.
I don't think that this has a cutoff like FP does -- I think that if your return time is in a half hour and you return an hour later, it's no problem, but I can't swear to it. We had a 30 min wait time and returned in about 45 min, and nothing was said.