The best way I've been able to explain tire pressure choice, is this method...
Yokohama H2S CT, starting pressure of 40 psi (about the point the bead was seated)
At 40 psi - VERY stiff... decided to back it down to 32 (tire recommended) "just to see"
At 32 psi - Very "squirely"... back end seemed to move around... a LOT
So... at 40 it was just too hard, and at 32 it was too soft. I started going up 2 lbs at a time from 32.
At 34 psi - MUCH better!!! But just a tad squirely in the hard leans.
At 36 psi - Tire stays true through all turns... just starting to get stiff again and "bump steer" starting to increase.
At 38 psi - Getting much too stiff. Bump steer getting annoying.
After all that playing around (about 4 hours worth)... I settled on anything between 34 - 36. After a few thousand miles riding two-up pulling a trailer, I've noticed an increase of 1 or 2 psi is needed to bring the tire back to the normal sweet spot.
With all that said... I would suggest that you follow a similar routine, except for that initial jump of 8 lbs difference. That much of a jump wasn't too smart on my part.