Ok fair enough there are sharper prints than Adams. But I've even seen some contact prints of his that were not super sharp so I assumed any unsharpness in his work had a lot more to do with old camera lenses, camera alignment, film holders etc. Tice does do a lot of contacts but I have some enlargements that are razor sharp, also some Sexton prints made without coated carrier glass (some from medium format negatives) - they are as sharp as I can imagine. In any case my point was only that of the various print makers generally held in high esteem as meticulous craftsmen, relatively few of the big names have bothered to install high tech lens glass in their carriers. By the way for reference, the coated glass John Wimberley uses is from Durst. I don't know who actually makes it.
Actually I'd be curious to know if Christopher Burkett uses special coated glass in his carriers. His prints are certainly sharp, even big ones from medium format negatives.
I don't mean to say it doesn't matter and that they use plain window glass between the negative and the lens. What I'm saying is that most good quality stock glass carriers from Durst, Saunders, DeVere etc are/were made with optical glass flats, and that the difference in print quality between using an "ordinary" grade of optical glass and better optical glass (and/or coatings/multicoatings) is likely immaterial - unless the enlargement factor is very large, which I didn't test. I tested up to around 10x (from 35mm negatives) with Schneider/B+W MRC glass (and other glasses) vs the stock glass and other than the difference in transmission I did not see any difference in print sharpness.
I stuck with the Schneider glass in my modified 35mm carrier because I already had it from the tests, and the MRC coating is super easy to keep clean. In my Saunders 4x5 carrier I stuck with Schneider coated filter glass (MRC coating not available on glass big enough for 4x5 even from Kreuznach) but did not see any difference between it and the stock glass - although again with 4x5 I did not try huge enlargements - only tested up to 6x. I didn't modify my Inglis 4x5 registration carrier for testing is it would have been redundant. The glass Inglis uses is at least as good as what comes in the Saunders.
Regarding fluid mounting, I think this is still popular with people who do certain types of scanning. I feel the same way as you regarding the risk. It seems like a disaster waiting to happen, even with the best technique. And I don't like the idea of having to wipe my negatives with Pec Pads and cleaning fluid. The whole thing is too messy and complicated for me.