Yeah, philosophical...
Would be good to sit with you for a while and pick your brains a bit, Mark,
Folks, please can we stick to the question I posed in the original post. Ok, exit pupil has been mentioned, and it will be big, and I knew that. Fine, finished. Not my question though.
If you don't have anything more constructive to add, then don't add anything else. I'm not interested in CAN'T. I'm after pushing the limits of what the gear can do. If it spins you out using a 40mm EP in an f/5 scope, then look the other way. But, if you can add to the sorts of aberrations or lack of one can see, please type away. THAT'S what I'm after,