I have nothing but admiration for you. You empowered yourself instead of being swept along with the flow. Walsh's book is hopelessly out of date, and is written from the POV of a man with a scalpel.
There is no question in my mind that AS should be the first considered choice for young men like yourself. Here are a couple of articles explaining why:/pcnrv.blogspot.com/2016/08/can-man-be-too-young-for-active.html/pcnrv.blogspot.com/2017/08/the-myth-that-younger-men-should-not.html
In long-running studies at the University of Toronto and MSK, more than half of men were able to avoid treatment for the full length of follow-up (15 and 20 years, respectively). The numbers are slightly lower at Johns Hopkins for the reason you mentioned - they have a lower trigger for treatment (too low, imho).
As for PNI, it does raise the risk slightly, but you will be monitoring it closely and you'll have plenty of time to react. Here's an article about
a recent study from Johns Hopkins about