Seems to me that it couldn't be too hard for WGT to exclude from your average, scores made at settings below some difficulty cut-off, which would vary for each tier.
So for Legends and above -- anything other than the back tees count towards RRs but do not count to average calculation -- same as P3s & P5s. You can play whatever you like - but the average will only count if the difficulty matches your tier.
Players would still be able to hammer away at unlimited play with many restarts - but this is still a far more meaningful number than what we have today.;