Activating a pump via an oil pressure switch.

[Rumcajs]

I like the way you draw it to match the factory diagrams.

Personally, I don't think both alternator charge and oil pressure need to be combined.
My reasoning for preferring the oil pressure model is that there's historically more risk of losing the alternator charge than losing oil pressure.
Of course, with a bypass on the lift pump you don't really risk being stranded but it's nice to have everything running as it's meant to.

Good info about the sub tank pump. I didn't know that.

What I'm unsure is if the alternator can support any load on the charge lamp signal cause as I dig deeper it makes no sense why Nissan ignores the obvious. I have re-done the diagram to keep up with the Nissan theme basically energizing relay via alternator field exciter circuit when engine is not running which seems like Nissan does the things e.g. subtank module, A/T temp warning light etc...
I also added variant with just oil pressure switch control.
Regards

Fuel_pump_circuit_with_alternator_Nissan_style_control.jpeg Fuel_pump_circuit_with_oil_pressure_switch_control.jpeg