Most important thing about the mount, to me, is that it’s lockable.Almost all my fast tele prime glass is EF but a strong E-mount would be fine for that. EF with electronics would be insane of course.
Pre-rec: 3 seconds seems like the minimum for the human reaction time.
But RED’s way is also pretty handy, 1st press to start the buffer, 2nd press to record inc buffer, and 3rd press to stop recording.
Also a cool option, if possible, to have a lot of vertical crop options in balance to higher framerate. Like full width but lower vertical resolution.
5. Please pretty please do PRO RES
But most important of all, to me, would be the dynamic range and color science. Ember is on the lower limit of acceptable dynamic range for normal outdoor use. If it’s proper usable outdoor it would sell like hot cakes.