n=1
I experienced occasional low fuel pressure issues both at takeoff for a few minutes and also during my descents from higher altitudes. Been off and on for several years, with no measurable effect on engine performance. Always transitory, but disturbing nonetheless.
At my 5 year annual in the spring, I replaced both the engine and facet pumps (obtained it from Van's so I'm not sure if was of a higher pressure spec or not). In over 40 hours of flight since them, while I may see a "higher" pressure warning on the ground - often in the yellow range on Dynon, I have not experienced a single instance of low fuel pressure during flight. Whether its 100% mogas or 100LL, hot day or cool, doesn't matter.
I'm convinced these low pressure issues are the result of under performing (possibly failing?) pump(s). Can't be sure whether its the facet or engine driven pump, but it appears to be independent from instrumentation or fuel mixtures. Maybe the long fuel line design of the RV-12 exacerbates it, but with "new" well functioning pumps, the problem was eliminated.
Just my own experience.