I'm also curious to find out about rest days after PE.
All my recent attempts at PE have been less than successful compared to my first when I gained 1" BPEL during 1 year by pumping 3 times per week for only 20-30 minutes.
During my recent PE phases, I'd do PE at least 5 times per week for many hours without much size increase.
I've just started using my vacuum pump again with a similar routine as my first the only difference is that I do a few minutes of manual stretches and pump for up to an hour. I found that doing PE too often made my cock a bit insensitive and staying hard became difficult. I also used porn for stimulus but after a while it failed to excite.
Doing it every other day seems to help keep me stay harder for longer and the routine seems to be more intense.
During my rest day I don't do any PE, the most I'll do is masturbate a little.
Has adding rest days into your routine improved results?