Yeah that's a fair point, the only option I can think of of splitting the RAP prebook system into ambulant and non ambulant, that way those in wheelchairs would always be guaranteed a slot. Obviously it wouldn't be 100% safe from abuse though.
Problem is, how many RAP users are in wheelchairs and how many are not. I'd hazard a guess at it being 75% ambulant and 25% non-ambulant, so it would be an even smaller number of slots available for the larger group of people.
A good start would be limiting everyone to one pre-book at a time per park, instead of three. But no doubt the MAP brigade would throw all the toys out of their pram if that was the case.
I wonder if this would make a difference. We multi book because you can't get slots for some parks for weeks/months so it would be interesting to see if a one booking limit would ease that issue or would not - if it didn't then it would severely limit how many times you could visit in a year.
One problem we find is that different members of staff managing the queues let different numbers of RAP groups onto a ride. For example we have occasions on Dragons Fury where it would be one RAP group per every 4 from the standard line, and then other occasions where it would be one RAP group per 7 or 8 from the standard line. Or on Tiger Rock there would be one or two RAP groups let through each time, but on another day it would be 4 or 5 - there needs to be some kind of consistency.