I'll take this thread back a level or two.

When I began photography my first SLR's a Zenit E follewed by A Practikamat (the first SLR with TTL metering it beat the Spotmatic into production) the lenses were coated, no issues with contrast. I had no problems either with Meyer & Sloigor optics/

It was only when I went up market and bought Sigma and later Hoya lenses that I experiences lens flare and they were Multicoated. That meant I made sure subsequent lenses were well coated and flare resistant. At the same time I was using coated Schneider LF lens for work again no problems but as I bought newer lenses I only bought multicoated except for my Leica M & Summicron.

Years (as in 3 decades) later I acquired my fisrt uncoated lens (a 135mm Tessar) and was pleasantly surprised by the quality but it did lack the micro contrasts I was used to, subsequently I bought a pair of T coated 50's 150mm Tessar cells of this or the LF forum and began using them instead that made all the difference.

What I'm saying is you have to get to know your own lenses, I used an early uncoated Triotar on a Rolleicord for portraits and it gave wonderful results on colour films but it was never the best Zeiss lens.

There's so many variables and I've a 1913 165mm f6.3 Tessar that will out perform some Tessar & type designs made many decades later and are coated. Many older lenses with poor contrast have isssues, the difference in final images between a good un-coated lens and a coated or MC lens is discernible if comparing images shot alongside each other but not necessarily obvious otherwise, and the difference between a good coated lens and an MC lens is even harder to spot.

The bottom line is uncoated lenses are old, if the glass is mint or in good condition you stand a chance of getting great images, but they age differently, sme may be hazy, others scratched, and the design it self may help enormously.