Having great sessions, lots of orgasms but one thing i dont understand...

I share your enthusiasm. Looking down and seeing a string of precum during an aneros session is a nice affirmation that I'm doing something tangibly sexual. When I see that, I want it to keep going, but it never does. In or out of a session, my precum volume always tops out at about the same amount. At best, I can manage a thin string of it that dangles down to my abdomen. But after that it stops, no matter what else is going on.

From what I've heard, it's just the case that some people naturally produce more precum than others. But there's a lot we don't know, and a lot science doesn't really care to investigate that much. (still waiting on those MRI scans of someone having a super-orgasm)

I don't know if it works, but I've seen posts in the ProstatePlay subreddit, that some take lecithin to increase their prostatic fluid volume. make someone leak precum. But I know for sure, that it is used by breastfeeding moms, too, to have more milk.

I guess this could help you to leak some amount of precum.

pygeum bark extracts and full spectrum can help, but they ever so slightly raise estrogen I've heard, and you don't want to take them forever. 

Beta sitosterol is what you want, its the chemical/amino in pygeum that makes pygeum make you make precum. I take isolated beta and yah I think it works better!

Drink more water than usual.

Don't smoke!! When I smoked weed I never produced precum, but when I went places or didn't smoke for like 3+ days, I'd be a faucet. Now that I quit weed almost a year and a half ago I produce a LOT sometimes while kissing my wife or hugging her I'll produce it. I used to jerk off for like 30 straight minutes and not get a drop. Now I can touch myself for a few minutes and it starts coming out.