Sorry, but I am now more confused than ever (not hard!). So there is a fuel pump relay on the CEM and a PEM? What the heck is the PEM's purpose then? I do seem to recall reading something about a fuel pump relay on early P2's that were on the CEM, but I thought that went away with the introduction ...

Yes. More than one year later and the fuel pump has been working fine. I was concerned that I might have failed to secure the driver-side level sensor to it's fitting during reinstallation. Decided it's not worth dissassembling to check and so far no problems.