Then I would just take a guess and say you ought to try bumping the pressure up a bit and start choking the material down. Usually this means spraying a bit slower, and/or increasing overlap a bit.
I've been fighting urethane wave myself with certain clears and have been getting good results by running my gun over the max recommended pressure. I go over by about 15% which for you would be 23 psi. Might be worth a try, little increments and see how it goes.