In the documentation for the bar number engraver, it's quite clear that the bar numbers were only ever intended to go above the staff. How do I override that behavior? It would make a part I'm working on look much cleaner (when they're set to the top, they make a habit of floating way above the main staff when the ossia staff is active in a system but not visible). This reddit user also found nothing useful except a suggestion of "make sure the bars line up between staves and fake the measure numbers, which only could work in highly specific cases.
Related, can I force chord names to display above the staff? It looks confusing when they display below the staff. The sample lead sheet and all the surrounding snippets have the chords above the staff, yet my part keeps placing the chord names below the staff. I suspect that the ossia staff is causing issues here as well.
Something from the aligning objects documentation seems like it should be useful in both cases, but I'm not sure how to apply it to the actual project I'm working on.