So don't use it.
Or rather use it then lose it.
When you were trimmed out at 12k and 350 and find yourself down on the deck and turning. Reach down hit control x for a sec, then hit it again to turn it off again. You've just reset your trim for the lower speed/alt. Rest of the time leave CT off. Granted its not perfect. But its a whole lot easier than manual trim all the time.
You want perfect, do manual trim.
You want easy, do CT on & off as needed.