How to add an ossium?

I'd like to know how I could add an ossium (plural: ossia, I think) to a score (which, for those who don't know, is a small excerpt of music, in a much smaller font, attached to the original showcasing an optional segment to be played instead of the original).

The reason why is, I'm working on a piano arrangement of Botanic Panic from Cuphead, but the in-game version has two sections that, because they are jazz solos, sound different from the soundtrack version. I want to add, as an ossium, the in-game variations, but I don't want to clutter up the music too much.

If this isn't currently possible, then this topic can be moved to the Feature Request section (too bad I don't know how many of those are actually considered; this topic might get lost in there).

Thanks in advance.