The Garmin GPS series have pop up terrain and obstacles already, with audio alerting avail to intercom, etc. I would think that an EFIS capable of generating accurate obstacle/terrain warnings would need the GPS WAAS enabled input anyway, so redundant? It would also need a huge 3D terrain database for comparison against altitude, groundspeed, vertical speed, even aircraft configuration and throttle setting, etc. This would all get very expensive for the average E-AB owner/operator, and typical Dynon target market price range?