Well OPT does say to stick within the family - use Hyper polish and Paint prep for best bonding of gloss coat and clean the car with ONR later on.
Paint prep is even suppose to have a catalyst built in for the coating to spread and bond better. But like you said it was not available at he time. Instead 15% IPA wipe was mentioned on the syringe instructions before gloss coat.
IMO if a coating lasts 12+ months its done its job. At that point you need to decon, clay & lightly polish either way.
I wonder what would happen if you used a non abrassive paint cleanser on it...perhaps it would deep clean paint/coating and help it to restore some beading (just my thoughs, never tried it).