Thanks BR, hopefully Kovid will chime in if their is something else that could corrupt or make problems.
John, I understand you position. I'm a linux user and have happily been using Calibre on linux for many years. I'm also having a Windows instance, and it would be nice to have the same library, since it's on the same computer anyway. (And the lib is too large to keep synching with a master copy, which would be easy if the lib was small.)
If no one gives a technical reason not to do it, I'll probably go ahead and do it and see what happens.
(I got backup.)