I have run my Rover with two fuel pumps since the early 1990s. I have retained the mechanical pump whilst installing a solid state Facet beneath the tank. I can switch on the Facet with ignition on but the engine off. I like having this option, although I can appreciate that it may not suit everyone. For the vast majority of the time I just use the mechanical pump, but if I need to, I can switch on the Facet for some extra help. It is certainly invaluable when the vapour lock rear's it unwanted head, then with a flick of the switch, the problem is gone in seconds.
Ron
Ron