When I had a bit of a bryopsis issue once, some targeted peroxide seemed to help a lot, but it was really only a few isolated areas. I have tuxedo urchins as well and love them, but in my experience pincushion urchins will decimate most algae in a way the tuxedos just don't. Bit of a nuclear option because they do chew straight down to bare rock, but they've done a good job for me at getting rid of everything from algae to vermetid snails at various points over the years.