I use Dick Nite MCU over baits painted with acrylic latex (various brands) and don’t have wrinkling. You didn’t give details on how exactly you apply the MCU, which may be the root of the problem. I have dipped but usually now brush MCU on. I use a 1/2” brush to quickly flood coat the lures, then hang them to let excess MCU drip off the tails. I usually go with a single coat of Dick Nite. When I first started using MCU I rotated the lures while drying because that’s what I was used to doing with epoxy. Big mistake. It allowed MCU to pool on the lure for too long, which caused wrinkling. Just hanging them up is the way to go, IMO.