Understood, and a concern I tried to address by installing meters - below from a couple weeks back was at the 2 generator HOT legs entering MAIN. Does this cancel your concern (I HOPE) for varying voltage?Worse than just having 240vac, any 120vac loads will have floating neutral so the 120vac house outlets will have varying voltage depending on how much 120vac loads are on each side of L1, L2 to neutral. Very unsafe and hazardous to 120 vac appliances plugged in. Very bad design! Shows total lack of understanding of U.S. split phase system. So can you believe the cord #2 plugged into one generator L14-30 outlet to house service entry is correct ???
I think part of your comment is at heart of my issue (concern) - "how to apply Neutral in this case". I wonder if it's something similar to installing High Frequency Inverters? How 240v is split when coming into homes from a transformer isn't same, and maybe source of this problem? My mind is parked on idea that AC needs to return or cycle back to source (the generators or home panel?).
YES, the L14-30 at the generator control panel works (how below readout was connected - so maybe I stop there and full-load test (I was successful in partial load testing the micro and HVAC fan).
NO, I wasn't successful testing Cord #1 (NEMA 10-50) and fried 2 power strips.