As for fuel contamination, this is a wide range of possibilities. Not sure what country you live in, but a lot of things can happen. First is too much Ethanol, this can be common where the fuel depot screws up and adds too much Ethanol. Pretty easy check with a tester the dealer should have. Water in fuel, underground tanks always have water in them, often it needs to be pumped out manually. If you fuel up shortly after a fuel dump at the station, the water can be stirred up.
Anyway, it is a wise idea based on some of what is going on to verify fuel quality.
A $10 smart phone app with a $20-$40 OBDII interface can monitor a lot sensor data. I would need to verify 100% if the Fuel Pressures are part of the standard OBDII data set as I have about 5 different tools I use and I do not recall exactly the what the standard OBD tool can monitor. I do know that things like High and Low fuel pressure, RPM, Timing, Voltage, MAF reading and many other parameters, this can all be displayed and at a minimum graphed on some of the mid level tools without a problem.
Given you do not sound like you have good dealer options, it would be wise for you to invest in an App and Interface even if they get you sorted for now. You may also want to invest some money in a mid level tool that would help you out. I have no problem dropping $500-750 as this will probably save this much with 1 repair. I also have a number of different cars within the family, so I need different model coverage. Where dealer labor rates are $125-$175 per hour, you can see how quickly a tool will pay for itself.
One thing I was surprised of when watching my the low fuel pressure yesterday while driving my 2024 was how much the Low Pressure was moving around. I figured with the lift pump and the high pressure pump, the low pressure lift pump would be a pretty stable pressure, but was not the case. I will confirm across a few other like vehicles just for reference. The high side common rail pressure typically operated between 750-2500 PSI as I recall.