I don't have one of these (thought about getting one, though), but I have a thought. If instead of powering the unit with an always-hot/key-on-hot source, how about from a source that's only hot when the engine's running?
Something off the oil pressure sender, perhaps? I guess if you could find something that went to ground when the engine's running or off, you could wire a relay in with +12V and use that to supply the unit with power.
A time-delay circuit would work, too, I suppose--wire it so that 10 seconds after key-on power, the idler unit gets power. That'd probably be the hardest, and require some electronics skills.
Any of these should work--basically, get the truck started, so the TPS/APPS does its calibration routine, then supply power to the unit, so it starts doing its thing.
The high idlers my Squad used (Ford Powerstrokes) worked like this. If setup correctly, about five seconds after the parking brake was engaged (or the engine started with the brake engaged), the idle ran up.
Someone around here put plans out for the same basic thing PS supplies--maybe he could chime in here...
Other than that, does anyone know of any electrical connections/fuses/CBs/etc. that go either hot or ground only when the engine is running/not running? On my old 4Runner, the +12 (or maybe the ground) to the parking brake switch was like this. Maybe a way to tap into the oil pressure sender?
Could be handy for some other stuff, too.
--Ty