I’ve seen other people ask this question - about this and more in general about this for the Star Wars attractions - I don’t know but hopefully they have some plan. Can’t just say, “ok, go out and then come back in the FP line” as people would abuse that.
Might just be a “too bad” scenario as not really sure how it would be handled
Could they link you to the party before/behind you (i.e. use them as the party you need to wait for at the end of the FP line)? I know that I'd be willing to be the "marker" if someone needed it.