Well if you took a long break you’re supposed to ease back into the vacuum pressure. Can you get a hand pump with a gauge to mate to the vacuum port, and monitor your vacuum level more closely? I find it helpful. For me right now, if I go to 4.5-4.75 in Hg vacuum, my glans is not liking it. But if I keep it around only 4 in Hg vacuum, my glans is not getting any pain.
I don’t think conditioning will really work unless you can accurately monitor the vacuum level. Because between using your mouth for suction, and then adding weight, you could be +/- 1 to 2 in Hg vacuum at any given time. And using 7 to 8 in Hg vacuum instead of 5 to 6 must be a big difference because I notice it even with a difference of 0.5 in Hg vacuum.
Then to condition, you could work at a vacuum level which is the most you can do without pain/negative PI’s in the glans. So like for me, if I go to 4.5-4.75, often times I can not complete my sets. So I picked 4 in Hg vacuum. (That is after the weight is attached). I will just keep it there for maybe a week, using a weight which is appropriate for that vacuum level. Then try 4.5 again and see if I can complete my sets. That would be a sign the conditioning worked.
Also another question, do you get pain in the glans, like any itchy feeling, or feeling of bad pressure, et cetera, during the sets before you get bruising? Because when I go too high on vacuum I have gotten clear signs, glans gets this itchy feeling and painful pressure that doesn’t feel healthy.