The first draft of that rule proposal I posted was an almost direct cut and paste from the UKAHFT rules. The one's they've been using for the past 4 years without all the problems we seem to be having with kneelers in FT, and those rules started life as the rules for FT.
The reason we're having a problem is down to marshalling - either by course marshals or buddy marshalling.
The bag puffing up under your leg isn't the only problem there is with people's kneeling positions, but it seems to be the main focus for the rule change.
A simple solution is just to state in the rules that the bum and thighs shouldn't be supported by your bag, and the rest of the rules are sufficient. It'll just take a season of regional and national shoots where the kneelers are marshalled and word will get round.
Some of the comments about kneeling changes seem to be focused on making kneelers more difficult. Is that a problem that we feel we have then?, are kneelers not difficult enough?.. Personally I think there are enough difficult shots on a course - GP or Winter league to separate the top AA grades and the top shots (AA's) are the minority of shooters in a competition, but the one's who all the rules seem to be focused on.
If you want to bring more people into the sport and continue to see it grow, then perhaps more consideration should be given to the majority of shooters - i.e. the non-AA's