I have wondered about these things and have mentioned it in orher posts.
Natural vs "induced" erections.
All the way into my 30's I would stay rock hard naturally for 4+ hours with the right partner(s).
Starting in my teens I would get hard throughout the day and night.
I would masterbate 4-7 times a DAY because if I did not I would have pain in my testicles/lower abdomen.
Plus my erections were extremely hard and painful.
Even now in my mid 50's I still get off 1-2 times a day.
I recently stated using trimix for "recreational" use. My wife and I bring in females to join us and so about half way through I go inject to keep the party going. For another 2 hours or so.
I seem to be a hyper responder to trimix. I take 1-2 units and am rock hard for 2+ hours.
But...my penis is not as large as it is when naturally hard.
Both in
girth and length. And the head never gets fully full with trimix.
I am VERY wary of trimix. Last thing I want to do is cause damage or end up in the ER.
I plan on trying bimix to see if that yields different results.
I like seeing these post as there is not a lot of discussion on the use of trimix/bimix overall.