^^ i don't have a clutch coaster to dissemble, but looking at G's videos on dissecting/explaining the hub, i think you can still put a couple spacers in there to control the slack instead of the bolt/plastic ramp system. Although this really isn't the optimal solution.
do you think it's the grub screw (the one to adjust slack amount) that's failing to hold its position with the threads? if that is the case, i wonder if it's OK to take the mechanism out the hub and set the screw with locktight then popping it back in. if you let the locktight cure for sufficient time (something like 20 hours) before reassembly, you should be able to prevent the grease from penetrating the threads and loosening it.