I think the BM rep's routine is a solid, good approach. The instructions in my X30 differed from the rep's in that it advises to remove the device every 5 minutes to massage/jelq. I am not sure whether the releasing and re-pumping is better or worse for BM results (there seems to be arguments for both). I was a little surprised that the BM rep would advise a different routine than the manufacturers manual.

Did you get a X40?
My BM did not explain how to measure mmHg. I am a little confused about this as well. It seems logical that you go in erect, notice where you are at on the measure, then pump another .5 inch. The problem I have is I am rarely fully erect upon entry and pumping causes and enhances an erection.....so I've actually seen an inch to 1.5 inch difference (and I usually only go to between 5.5-6 inches on the scale when fully compressed). Sorry I couldn't be more help on this...its not critical to the function, but it would be nice to calculate the pressure.
I can help you on BM use tips: trim pubes quite low (or shave), warm up (balls should be loose, so as to not get sucked into or against the BM cylinder. I use it in the shower (not when I am taking a shower), fill the cylinder in the sink with warm water, step in shower, pull down on scotum as I slide the BM into place against (a little water is lost/displaced from the cylinder), check placement and gently pull down on testicles to make sure they are out of way, then compress the gaitor as you focus on keeping the "comfort pad" pressed firmly against pelvis. Then allow the gaitor to recoil out as you feel the pump engage and your cock becoming more engorged. Sometimes you will get air in the cylinder on the 1st pump and you either have to pump the air out and get it to seal....or restart. You will know if its right because you will feel and see the pump at work. It takes a little practice, but feels great! Enjoy!