ABsilicone sells a pumping sleeve. It takes a literal dogs age to get it from then though.Autoextender sells highly similar sleeves for their Xsleeve system. I’d buy a medium hardness thin sleeve for this experiment.
You can cover the glans with a condom. This is an austfred technique to prevent glans blisters.
I water pump using a Mr fantastic pump. I found glans blister formation was much more likely with water pumping probably because the wet glans skin made it easier for fluid to move between the skin layers. Baby powder, on the glans, which is a drying agent helps prevent blisters and the condom keeps the glans dry.
Got a blister a few weeks ago when a condom broke (after multiple uses) while in the tube and I noticed it too late because of the heat wrap around the cylinder.
I currently dynamically pump in the range 3” - 10” Hg having lowered it from 3 “- 12” Hg after the blister. Believe you are more sensitive to blisters after getting one thus the reason for dropping to 10” Hg max. I initially dropped to 8” Hg but found I get better expansion at 10” max with little ill effects but still would drop to 8” max after an injury for a while just to be sure.
Austfred.