Probably depends on which diversion you are looking at as each surgeon probably has their own that they are most comfortable with. I am linking you with a ranking of hospitals which of course has the subset for bladder cancer and the further subset of surgeons. See: https://health.usnews.com/best-hospitals/rankings/cancer
MD Anderson, Sloan Kettering, Cleveland Clinic and Stanford always have high marks but there are many others. Northwestern, John Hopkins, U of Iowa, Michigan, USC among others. You are looking for one that does 25-35 a year and I'd want someone that has been doing these for 3-5 years.
DX 5/6/2008 TAG3 papillary tumor .5 CM in size. 2 TURBS followed by 6 instillations of BCG weekly with a second round of 6 after a 6 week wait.