The pic Kelvin shared is the orientation I was advocating as well - at least if the pathlength distance from the top and bottom of that mid to your ears is equal.
The link shared on the line arrays - I think that was shared to point out the negatives on a line, and that's exactly what led to an install I did years ago... Essentially an intentionally-nearfield line array, but then mitigating the negatives and turning them into what turned out to be some real positives in ways I didn't even expect:
https://www.caraudiojunkies.com/showthread.php?p=59810
(I added pics a few posts later.)
I may actually be looking at ribbon tweeters myself to play with, definitely carefully oriented, to see if the experiment here can also work in the much more difficult upper frequencies.
My opinion - if you have those already, and they sound awesome and have the output you want - you should at least give them an experimental attempt. If it works out, then tackle the cosmetic fabrication and upholstery.
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