Anything that builds up “a lot of pressure” is a mixed blessing.
On one hand, if your tissues can withstand it…it can lead to faster expansion.
If your tissues can’t withstand it…injury! That is why there is always warnings attached to clamping and other techniques that build up higher pressures…people HAVE been injured doing it.
This technique sounds like it can generate high pressures. I think it is prudent to be careful here.
My personal opinion is lower pressures over greater time, combined with sustained heat is safer.
The heat softens the tissues enough that you can get good expansion with LESS pressure. The heat seems to soften the connective tissues without compromising the strength of the blood vessel walls.
It is much better to avoid a major injury to your unit, than try to recover from one.
Maybe doing regular jelques and the like for the first several sets ( under heat), until you begin to see some expansion… and finish with one or two sets in the squat position.
Limit the time and pressure. That may let you see greater benefits with less risk.