I went back out for another series of tests. This time I simply jumped the fuel relay socket to activate the pump without the engine on.
All I got is 2.3 Bar as the main pressure.
I put back the relay and started the car and the most I got was tad below 4 Bar.

I then went ahead and replaced the fuel pressure regulator (again) and I got the same results.

h, the car smells funny when the engine it's on. I get an eye burning sensation and almost feel like throwing up (I am not working in an enclosed area)