Congratulations to All Clear,
Since I have low-grade bladder cancer, I have not received BCG, but instead Mitomycin C for 8 weeks and maintenance for half a year. I am not a doctor but this is how I have got it: It is debatable whether maintenance treatment with chemo like Mitomyin or Valrubricin is effective, at least for a longer time. Although BCG and Valrubricin are administated in the same way, they work in different ways. Therefore, I am skeptical to Valrubricin as maintenance treatment after BCG. IF the cancer recurrence, Valrubricin can be an alternative to removal, but you and your urologist should carefully consider the risks associated with that.
Since you have had two rounds of BCG, In one way you have already got some maintenance. It may well be that you have good enough protection.
I think your urologist assessment seems reasonable and wise.