I think it might work, and rather fairly so, if they would grandfather and freeze everyone over 20, then cap 20 as the max going forward. yes it would take a whike to burn off the top 10 yrs but EVENTUALLY would. And the motivation would be to use points earlier rather than hold out impossible hope. If you wanted to “hold out” for the top draw, at least it would provide some clarity that once the top is burned off, anyone with 20 would have a lotto chance, which isn’t to be sneered at given the 0% chance they have now. Nobody should get too pissed, nobody gets screwed over too badly, revenue keeps rolling in, anybody not “holding out” is pretty much unaffected except normal creep at the lower tiers, but at least it wouldnt be a mathmatical time bomb.
Another thought (again with the grandfather and freeze those already over 20) could be to cap PP at 20 and then anything over that is a bonus point only. So it becomes a weighted lotto at the top. would make it more exciting for more people, thats for sure!