It’s been a while since Maria’s comment, but the hover does seem to work for me by now. I’m interested in hearing from Coda themselves whether the Lookup function really works like a shortcut to the Select List function preset to the table you select? If so, this is a perfect solution (while still being a bit hard to stumble upon short of this thread).
EDIT: I didn’t search long enough; in this discussion Coda does explain how this works and some best practices…