keystring I now know that you can save Finale music as XML (looks like code) and if I drag XML into Finale it looks like music again.
True, but the details are important. For example, if one has fingerings in a score which is being as exported as XML, these are possible problems.
Searching "musicxml import loses fingerings" I got these results.
Verovio: The issue is reported in the Verovio GitHub issue #803, where fingerings are not preserved during import from MusicXML. The problem arises from the lack of positioning information in the <fingering> elements, causing the fingerings to be automatically placed and potentially misplaced when loading the file into different music notation software.
Dorico: Dorico imports fingerings correctly from MusicXML files exported from Finale, but not from Sibelius, as Sibelius does not use the <fingering> element.
MuseScore: When copying and pasting measures with fingerings, the fingerings may not be retained, especially when pasting into a tablature staff. Additionally, exporting to MusicXML and importing back into MuseScore may also lose fingerings.
Validation Errors: Some MusicXML files may contain validation errors, which can cause fingerings to be lost during import. For example, exporting a score with string numbers 0 (indicating open strings) may result in a validation error and subsequent loss of fingering information.