My portable compressor is a DeWALT D55140. It produces max pressure of 135 psi - with the motor running - which is more than enough to fill my tires. The trick with all small compressors is too keep the motor running. If it the motor stops, fill rate decreases until the tank to empties to 90 psi at which time the motor restarts. Just remember: 135 psi is available only with the motor running. I usually just pull the pressure relief valve next to the regulator to start the motor - and then run it continuously until each tire is full.
I also use a TST 507 RV TPMS and am now quite familiar with pressure changes as I drive.
I used to fill my tires to 100 psi - just to be safe. I think I loosened a few teeth along the way
. With the TPMS, I have found that my tire pressure increases about 10% after about 20 minutes of driving. That means we traveled at 110 psi most of the time.
I have since weighed my coach and now follow Michelin's recommendations. We now start each trip at @86 psi all round. After warming up, we actually travel at about 95 psi. Much smoother ride for sure.