I just changed to another aluminum free wheel. I am one of those with the high mileage… 8000-1000km EASY. I am in Singapore - where we have great clean roads, ride only in fair sunny weather - and the occasional “caught in rain”. I clean my bike after every ride.
I do have 2 plastic freewheels but I not used them — YET because I am happy. with the life span of my aluminum free wheels.
Sorry i can’t be of further help. Strida EVO FYI here.