So digging into the flipper fade issue. I now have the fan brackets made and have started getting baseline temperature ranges before I kick on the fans and see how much (or if) they help. These are the same fans as the SFAN-001s I sell to quiet the meanwell Stern 500W power supplies, so they're small, quiet, and only draw a small fraction of an amp each.
The flipper coils definitely heat up, but since I've never tested them before I don't know what's normal yet. In my first relatively short game, they went from 76 degrees (basically ambient room temperature) to 115 degrees when the maybe 5 minute game ended. Strictly from (perhaps flawed) observation, holding seems to be worse than flipping, but both raise the temperature of the coils. Left and Right max temps were within 1.5 degrees on the game I played when it ended, which I thought would be a wider range based on what flipper I favor.
The mount the brackets use piggyback onto existing hardware on the underside of the PF, so it will be completely reversible.