I never really understood why testicle size is so important to some. Some say they are afraid some woman may notice or even laugh at you. Ridiculous, I doubt most care or keep tabs on your exact ball size. But whatever.
Regarding testicles and gear, and this may be too much information, they do not necessarily shrink to peanut size. I would say for me they get maybe 30% smaller on average but the size changes constantly even after decades on so there is some type of activity still going on. Sometimes they might be as big as ever in the morning and then 50% smaller in the evening, really quick changes by the hour. I noticed this trestolone I was running felt more suppressive than a lot of other gear judged by testicle size and semen volume. Supposedly you are either shut down or not, little in between, but I think that may not be the case. Would be interesting to know if sperm is at zero, never got it measured.
There is some theory that keeping the testicles inactive, in hibernation if you will, will keep them younger. Not that it would matter either way but who knows, maybe you might be better able to get someone pregnant in old age if you used steroids.