I often find myself in need of offsetting some tempo or rehearsal marks for certain parts but not the full score but tags won't work in this case since I can't have two marks at the same location on a single context. It is a lot of work to duplicate the whole context just to differentiate a few markings.
Are there any tricks to apply tags on specific marks or markups only? That would be so useful
Can Lilypond be made aware of which file it outputs to? if file A.ly do this else if file B.ly do that else do something else. Maybe that doesn't make sense.
It would be cool if I could specify the offsets based on a file by file basis.