High force is not what the vac
extenders are good at. The other posters are right that the purpose is to be worn for lighter forces for longer hours, I've had many posts on this exact subject.
It's somewhat counterproductive to argue with your methodology if you're definitely seeing gains, but it's also impossible to argue against higher vac forces being to blame for sudden blisters and ruptures, even if one has spent hundreds of hours adapting to the units.
Having said that, one can also get blisters/ruptures using just medium forces if going for huge lengths of time. While the vac units aren't great at doing high forces, trying to do higher forces for brief periods of time might actually be safer than doing medium forces for protracted lengths of time (like overnight).
If you're going along ok in that sort of 'high intensity interval' method with no blowouts, great job. -- If you want a higher safety factor and to explore the vac's effectiveness more in line with the way they were designed, back off of the force quite a bit and go for longer time and track how that seems to be going for you.
The more/longer time you go for, the more you'll probably need to back off of the forces used if any blistering (or -strange- toughening of the glans tissue) is a problem .. because the blistering can occur across-time as well, if it's a
lot of time, even at lower forces.
- I feel like I could simplify that information on a second try ...
If what you're doing is working for you, and you're not getting occasional destructive results from it, keep it up .. even if people disagree with it.
If you decide to go for waaaay longer times, then you'll want to also go for waaaay lighter forces at first .. because longer times with medium forces can cause destructive issues as well.
For the dryness ... look up a product called NaPCA (sodium pyrrolidone carboxylic acid) , - not really an 'acid' .. just a salt compound in a spray bottle .. either regular or with aloe. It's a humectant salt that absorbs moisture from everything and then holds it in the cells. Remarkable stuff. Supposed to be the difference between baby skin and old people skin. One slight caveat if you're currently banging people ... a highly PCA moisturized penis seems to have more frictive drag .. and that's going to add up to extra sensation during sex which might negatively affect one's ability to go as long as they usually would. So, just keep that in mind ... or just only use the PCA on the glans and not the shaft.