wrote:

But none of these ever reached the image quality levels of Leica, which
makes
me wonder if my earlier proposition that focal plane shutters yield
sharper
results isn't true.

Rather thin "evidence". You can't compare Leitz lenses to, here, Topcon
lenses, or even unnamed old thingies on ditto cameras, and draw conclusions
about the releative merits of focal plane vs leaf shutters, regarding
shutter induced vibrations.
Come to think of it, it's silly to the Nth-degree to even consider doing so.