This is true (the nature of the OP's question), but the OP did mention that the HP 23's were not suiting him. So, this being the case, it seems you're recommending that he stick with 23's at high pressure and get a new frame.

There are other factors, I believe, that pros and aspiring racers are running 23's as a norm - weight being one. The narrower tires will have less rotational mass and will accelerate more easily, etc. Plus, many race-spec tires are not available in widths wider than 23.
The physics have been analyzed, and a significant enough number of the results have shown that for a given pressure, the rolling resistance (driven by deformation) is actually lower with a wider tire.
Other factors such as wind resistance, availability and rotational mass help build the case for narrower tires for those concerned with these things.

I quite frankly do not believe that the incremental rotational mass and wind resistance is going to make a difference in the context of this post - larger rider, non-racing, discomfort with higher pressure, etc.

So, to the OP, as you can see the whole rolling resistance topic is a can of worms. Hopefully you can glean enough from the many perspectives here to form your own opinion on what will suit you best for your needs.

Cheers,
Michael