A T of 270 is very low - how low does he say it must be before he will prescribe it?
There are a couple of small non-randomized studies that support testosterone supplementation in treated men. You can try sending them to him and asking for another discussion:www.jurology.com/article/S0022-5347(13)00259-0/abstractwww.jurology.com/article/S0022-5347(16)30307-X/fulltext
Another approach might be to try to stimulate more natural production of T from the testicles using human chorionic gonadotropin and Clomid. Maybe he's willing to prescribe those for you.
My Uro does prescribe T for RP-treated men after they have a convincing series of undetectable PSAs. There are many Uros who do these days.