Very interesting Tony. I used to run a RRFPR with the stock turbo injectors, ramped to 65psi of fuel pressure on 14psi of boost. It was very repeatable. I used to check it with a bike pump on the regulator with a gauge, while watching the fuel pressure gauge. On a hot day in Syracuse, at the convention, I pumped out 265 RWHP with the stock motor and ECCS in place. However, I have no clue (lol) looking back, if the AFR's were anywhere near OK. It ran great, hit Watkins Glen International, and drove us home with the A/C on. Nowadays, I have more info and can see the fine detail of what goes on behind the scene thanks to Megasquirt. I have my tune really close and rarely see my EGO corrections go much over +/- 5%. However, when the system gets hot, you can see the EGO corrections pinning in the +20% realm (only at idle and very low revs), where I limited WBO2 authority. Therefore, I know I am dealing with a hot AND fuel variable condition. I will install the new regulator anyhow, and play with the pressures a bit...experimentation and learning. I may end up sending the injectors out to get blueprinted again, for shits and grins.
Back when I had the rail dead-headed, I had a nice cool fuel tank. I had the regulator over on the passenger fuel rail where the fuel came up, and went back to the tank with minimal heat exposure. Now, I recirculate the fuel, so it stays OK for a longer period, but eventually still gets into the "leanies" as the tank heats up.
I am a sucker for blue anodized stuff, but right now, I can't find to many spare yen hanging around. Fall and Winter are near. Nothing like the feel of a turbo Z, in the cool air. I still think my system would like some additional fuel pressure so I will give it a try. I always learn the hard way.