Mach-
Please keep in mind that all I or anyone else can do is relate information and suggestions gathered from personal experience and consensus. How you process that and use it is entirely your call, and I would never encourage you to go against your own better judgement; if you feel it best to cool off on the hanging you should.
That said, given all of the information you have provided it appears to me that you are experiencing a pretty common problem. The fact that you can hang lighter weight - as well as the ten pounds up until a point - and not suffer the discoloration, suggests vascular stress and general conditioning as the culprit.
Regardless of the device you use, circulation to the glans is partially restricted. This is due to a combination of the device itself shutting off some of that blood flow as well as stress being applied to the veins and capillaries of your unit.
As these blood channels become conditioned to stress, blood flow improves.
As we go up in weight and add new stresses to them, blood flow decreases.
In many cases, the stress becomes overwhelming and blood flow completely stops.
Think of it in the same terms as your maximum weight: You know not to exceed a certain weight amount because it causes physical pain to do so. As you become more conditioned, you will one day be able to exceed that weight, and more.
The same thing applies here: The veins and capillaries in your unit have met their max weight - but instead of crying out in pain they reveal their stress in the form of discoloration. The stress has stretched and thinned them to the point of shutting off blood flow.
My personal opinion is that working through this will yield better results than stopping a routine. Not hanging will cause these internals to decondition and likely make the problem worse - or at the very least make the problem a persistent one.
The good news came when you said the discoloration quickly fades and a normal, healthy pigmentation returns. Blood flow has been shut off for a time, but not long enough for damage to be done. This is why set time is kept to a standard 20 minutes (never exceed 20 minutes!). Tissue damage caused by oxygen deprivation usually begins at around the 17 minute mark - and given that discoloration generally happens late into the standard 20 minute set we are keeping ourselves within a safe range.
Mild jelqing between sets does a great job of fully restoring circulation to the glans.
Whatever you decide, always approach complications like this with a great deal of caution. Be smart. Be careful. Especially be on the lookout for numbness; although it is a totally different issue (pressure exerted on nerves) it is a villain.
>I check the head for temperature throughout the set by touch, however since I'm doing btc, it's rather difficult to see. Next time I will stand up and check it occasionally. <
Periodic touching of the glans is very useful, so keep doing that. A way around the BTC “glans out of sight” issue is to keep a hand-held mirror nearby and use it to observe the glans. Make sure to keep the area well lit so you get a very accurate idea of how your color looks.
Do not confuse blood spotting and bruising for tissue death. I personally have not come across a report of tissue death - I can’t say for certain that it hasn’t happened - but I see plenty of instances of bruising et al. These battle wounds usually fade pretty quickly.
I hope this all helps.
-Cap