From what I know nothing has changed, I haven't seen any threads lately about BP rash from folks. Seems to have stopped. I think people weren't checking there backing plates when they received them to make sure everything was nice and tight. I can assure you you need to check as mine that I just received today was loose. Depending on weather I hope to give it a go this weekend.
Oh yeah they (Flex) recommend lubing up the felt ring (need to remove BP) before first use with a "light" oil. I'm going to use some 5w20 I have.