Is it possible to have good fuel pressure and have lack of flow getting to the injectors cause by a clogged fuel filter?
on any sane fuel system, lack of flow would cause a pressure drop as fuel flow requirements exceed available flow, so no. you'd see it on a pressure gauge, although revving in your driveway is quite different from driving.

you could also have intermittent fuel pressure loss, might not be the pump, could be loose clamp in tank, cracked pickup hose, something like that.

i agree that switching ECMs right now would be a bad idea, in fact a different ECM might 'tune around' the problem more easily, but you'd still be burying whatever is wrong.

if 'resetting' or reflashing or whatever temporarily cures the problem, i'd say you have some kind of problem with closed loop. why don't you burn an open loop bin and see if it behaves itself?

it's also possible your ECM is flaky, but you'd probably see other evidence of that

i'd be interested to see some logs of when the weird behavior happens