ASFKAP,
One of those "more able minds than mine" obviously resides in your head!! Yous schematic seems to wrap up the argument. As Isaid, I was relating a story fifth hand, no I havent seen it in a sim (though I'll give it a try next time I am).
I've never flown the 1/200 series aircraft and was suprised to hear both the LTU and the PTU were additions to the "EFIS" series. Does anyone know if they were added to meet some subsequent certification requirement?