Yes, I'm here, and still making Rocketchips. Please shoot me an email thru my website:
www.werbatfik.com/ecu.htmYes, clamping the return is a very bad idea. You're sending way too much pressure thru the injectors and may harm the FPR. Risking popping the fuel line off is asking for a burned up car, too.
An 'old school' way of achieving what you're doing is with an "FMU": "fuel management unit" (a bit of a misnomer) which is a Rising Rate Fuel Pressure Regulator. They raise the fuel pressure X number of PSI for every pound of boost you add. (you can get them with different rates) This was a marginal solution for originally nonturbo cars running low boost pressure without getting into ECU work.
You don't want to go above 12:1 when you're under boost. Your numbers are showing dangerous conditions inside the engine. Lean conditions under load make the combustion chamber run hot, and can melt the pistons. (I have done this in the past, it was not fun) I can't explain the super lean numbers after you unclamp it, I am unaware of any temporary fuel trim in the ECU (that is more of a modern ECU thing) It's possible that your fuel pressure regulator is damaged. If you remove the vacuum line, does fuel come out?
Send me an email and we can discuss some Rocketchip options