Another possibility would be the option of displaying down- or up-pointing arrows when pitch attitude goes past a specific limit, say +/- 30 degrees, or when the earth/sky line is no longer be visible. That would provide some easy-to-interpret recovery guidance in case of an unexpected unusual attitude.
Wow, that sounds like an accident waiting to happen if you ask me!! (I know, you didn't...sorry) That could induce a dumb-arse pilot to split-S inadvertently if he simply pulls (or pushes) in the direction the arrow "tells him" the horizon happens to be.
Any time an instrument like the -D10[A] starts "instructing" in form of arrows or other "hints" like that, I personally think you're treading in unsafe territory.
Think about it this way...if you used a conventional gyro-based artificial horizon, what information would it provide in extreme pitch attitudes? Essentially nothing. I'm not trying to make excuses for the Dynon EFIS to provide less than it possibly can, but I think it's important to delineate as clearly as possible the responsibility of the pilot and the role of the instrument.
I personally think numeric indication, in terms of degrees of pitch indicated next to pitch lines (in 10-degree increments), would be a simple, SAFE indication.
Just my 2 cents,
)_( Dan
RV-7 N714D
http://www.rvproject.com