While I understand the “theory” of moving the pump, I’ve seen a lot of issues with pickups over the years that have had that particular mod done. From poor fuel line connection, to too small of wire and corroded butt connectors. I still run a pump in the stock location. It’s easy to get to and by monitoring my fuel psi I should be able to tell if it gives up the ghost. I’m only on my 2nd lift pump from the oem unit that started weeping after a year of ULSD (Cummins made an upgraded diaphragm).

FWIW I see about 12psi at idle and on a long steep grade towing it can drop to 3-4. Not worried in the slightest.

The intank pumps (retro-fit kit) I’ve tested over the years would drop close to zero, but rarely went into a vacuum. The ones that did go negative I’d often find the strainer/inlet in the pump loaded with debris from “dirty” fuel sources (in bed steel tanks, steel farm tanks, construction site vehicles). Fuel volume to the VP is much more important than psi.