I understand the protection GFI provides..... been meaning to grab some of the plug in adapters for my portables that I think ur posted.
But, I'd prefer them as an add-on like that for my use. I understand gfi receptacles are built to a certain price-point, so they do seem a bit failure prone. The LAST thing I want to have to mess with is pulling out a built-in gfi receptacle from a generator during emergency operation.
Borrowed some power (with permission) from next door last outage (my generators were good to go, just didn't feel like messing about outdoors that day). My neigbour is fed off a different feed than I, so we sling cords accross the lawns accordingly. I'd looked at my neighbour's panel last Spring, as she had a power outage in the attached garage. I couldn't find anything wrong, so advised to call an electrician. Problem turned out to be a faulty gfi outlet on their deck, which was the same circuit as the garage.
Fast forward to the recent outage..... couldn't plug into the New gfi outlet sparky installed on neigbour's deck. At first I thought there was some shutter type layer over the U ground vertical pins, but no, it seems it was installed with something like a thick layer of nylon sheeting behind the bezel. GFI is for safety, and I guess this delivers, as you can't plug anything into that receptacle.
Told my elderly neighbour I'd pop that gfi cover off the next time it's a dry day and I'm home, and see what's going on. Maybe I just had a brain-cramp looking at that the other night, but it seems like there is a layer under there that should have been removed at installation.
Complexity vs. Reliability vs. Safety.......
Rgds, D.