Why your hormones are NOT holding you back in any way from more gains...

First off, we're talking about ENDOGENOUS TESTOSTERONE AND HORMONE LEVELS.  Not EXOGENOUS.

The latest and most up to date hypertrophy and muscle growth review did include this topic in it this year and they TELL YOU THIS.
PMID: 41276164

"It has been posited that both acute (i.e., minutes, hours) and chronic (i.e., days, weeks, months) fluctuations in systemic anabolic hormones, such as testosterone (T), growth hormone (GH), and insulin-like growth factor-1 (IGF-1), are internal variables with a causative role in RET-induced muscle hypertrophy.41,42 On the contrary, previous research that has directly investigated this thesis has yielded no support for the concept that acute RET-induced changes in these anabolic hormones mechanistically underpin increases in MPS or skeletal muscle hypertrophy."

There's also a whole meta analysis that shows that men and women gain muscle at the same rate and the same overall relative amount.

PMID: 40028215

So if endogenous testosterone levels played a role WE WOULD NOT SEE THAT!

Again the data is overwhelming that it is your androgen receptor content and not your free or total T levels that impact muscle growth.

PMID: 30356739

As long as you're in the normal range (yes AS WIDE AS IT IS!) you're literally already optimized hormonally.