In all serious, you can take the recommendations here from similarly weighing folks, but the best thing is to take some time with your bike with the load you'll be using, and trying diff pressures on diff types of paved surfaces and feel the differences yourself.
For ages I never really thought of my tire pressures, would put them to mostly the max pressure and thought it was best. Commuting along the same route and on diff bikes made me become more aware of how diff tire widths and pressures felt along my paved regular route that has a huge range of surface quality, from great to terrible rough bits.

the one thing that has become clear to me over the last bunch of years is that the views that you stated about highest pressure not being the fastest, to me this is absolutely true. A super hard tire may "feel" faster, but the reality is that the diff with lower pressures (to a certain point of course) is not really noticeable on good pavement (pretty much same speeds) but extremely noticeable in a good way over bumpy pavement--you dont get beat up as much, which is a win for your body, and you can hear and feel that less force/jolts are going into your frame/spokes/rims/panniers.

bottom line, get out there with a good pressure gauge and try diff pressures, if you are the slightest bit attentive, you will notice the differences. Just dont get caught up in the whole thinking and feeling that a hard, jarring tire feel is faster.
You will notice though that often a few or 5psi will make all the difference in how a tire rides comfort wise. On my recent trip, going from 50psi to 45 on the rear, and from 45front to 40 or 42 made a real diff in riding comfort.

I was using supremes also, but 26x2, so much lower pressures, but I was still impressed by how the tires rolled in general--and as they are fairly supple tires, take advantage of lower pressures (opposed to max pressures) so that you can take advantage of thier nice feel and ride due to the supple sidewalls.
**Because the sidewalls are so thin, you do have to be careful about not riding up against a sharp rock or whatever, but using common sense is fine.