About that "Chasing the low throttle setting", it seems like I'm often changing the trim tab after flying out a half tank or so. Sometimes not, sometimes the idle creeps up as the tank empties out. I see this on glow and gasoline engines.

No big deal, that's what trim tabs are for. Likewise the other trims, you may find yourself changing control trim, from time to time. I remember my old 4-star, the outside temperature would change the length of the plastic pushrods - and that would require a trim tab reset.

Good luck,
Dave Olson