A friend of mine has a microscope with eye pieces and to me that felt very uncomfortable and still required bending the head forward a bit. The benefit of it being stereo made not that big a difference for me. It will be a matter of getting used to it.
And yes the mantis would be perfect, but at more then 10 times the price of what I have now, way to expensive for a hobbyist like me.
Proper ergo eyepiece would mean you have a straight neck, its hard to find.
Well. Fark Aliexpress and "Eakins Store" in particular
store Id = 836673
I ordered "Industrial Binocular Trinocular Microscope Camera Stand" US$99 and "Trinocular Stereo Microscope Head" (their Choice program) US$150
Tried to return both because exit pupil was so small it was unusable. The head (Choice item) was refunded in full. But stand was partially refunded, just US$76 out of $100. Support in two separate chats said "yea, we'll fix it, have a nice day sir", Nothing was fixed. $75 refund came through, Appeal button resulted in "the newly updated proof from the local warehouse. Since the item you return is different, we cannot arrange refund for you.". I sent it back exactly as I have received it.
/rant lol
You can link to the item in question to help us out. Was it this one?
https://www.aliexpress.us/item/3256806802179634.html $99 is very very cheap for a microscope head. You can't expect quality at that price.
I don't know what "exit pupil was so small" you are talking about the field of view?
The link above has 10x20mm eyepieces, so a 20mm FOV. Which is OK, though its worth spending a few more dollars for 10x22 or 23mm.