Ah, I see what happened here. Right now we have a single ProposalListWidget that contains a number of labels. The first is the "best" or "preferred" label, and all other non-preferred label widgets are set to hidden. When you click the "alternatives" button to expand, the non-preferred labels are toggled to be visible.

I think what's needed to get this to work with OOjs is to maintain two separate ProposalListWidgets within a single FacetWidget. The first one will only have the "preferred"/"best" label and then the second list will contain all other non-preferred labels. The Alternatives button will toggle the visibility of the second ProposalListWidget.

Gotcha. This is how I originally designed it so it makes sense for how we got here. This showed up in user-testing as confusing. It seems like it could be quite annoying to try to move the "alternatives V" button up above the alternatives. If that is the case, I can look for *alternative* visual strategies for signalling that alternatives are less important or real than the best/preferred/consensus label.

Change 583034 had a related patch set uploaded (by Kevin Bazira; owner: Kevin Bazira):
[mediawiki/extensions/Jade@master] Moved "alternatives V" to the top of the list of alternative labels.

https://gerrit.wikimedia.org/r/583034

Change 583034 merged by jenkins-bot:
[mediawiki/extensions/Jade@master] Moved "alternatives V" to the top of the list of alternative labels.

https://gerrit.wikimedia.org/r/583034

Nice one @kevinbazira! This is a much better solution than what I had in mind.

+2'd & merged