Only tested it a bit briefly, but it seems to work very well.
You can now scan a folder containing classical tracks that don’t necessarily make-up a complete album or box-set, and (if they already have MusicBrainz id’s?) the process is not slowed down by the plugin looking up data for non-present tracks anymore.
I am only wondering if the wordings ““Do not run Classical Extras for tracks where no pre-existing file is detected” will be explanatory enough for (less-savvy) users that don’t know where all this came from.
Just for my (layman’s) understanding: Is this latest change you made related to indeed checking for non-present files, or does it check for MusicBrainz ID tags in the files already being present?
Assuming the second, my personal workflow now would probably be to first run classical tracks/folders through picard without the plugin active, and then a second time with it activated.
Assuming this currently would indeed be the proposed method for such cases, it would of course be nicer if only one run would suffice.
And perhaps avoiding any additional (possibly confusing) setting necessary to decide on this matter beforehand.
But that might then require some pop-up alert when the plugin encounters such incomplete albums/box-sets?