I will share my case and offer what I choose to do.
Had Gleason 6 in 7 core and one upgraded upon second opinion to G7 so after a year on AS I had SBRT
First thing my doctor did was stopping my testosterone replacement. My T levels are rock bottom hence my need for TRT
I was a basket case and eventually found a clinic and went back to testosterone. Yeah yeah, I heard about "Gas on fire" with PCA and testosterone but I happen to live in my skin and could not deal with the emotional toll. My T had dropped to 25 and I was a sad crying emotional wreck so that was why I found a clinic and BTW withheld my PCA diagnosis out of fear. I did alert my oncologist and PCP
So yes I might have taken a chance but it was my choice.
I cannot give advice as you know but I will add the PCA is usually very slow growing and second a undetectable PSA is a great sign!
I know what I would do in your case but that is your choice

Glen