Welcome, urban_!
Another interesting model is what Miami-Dade just did last month: a non-binding referendum on interest in expanding rail transit. Not necessarily voting on funding yet, but giving officials clear(ish) direction on whether it'd be worth putting the effort into planning out these kinds of systems to seek funding for. 80% of voters in Miami-Dade voted yes on that. I would not be surprised if such a vote in Jacksonville reached similar margins.
The straw poll would have to clearly, and explicitly, state that neither Skyway nor U2C technology would be considered should the City (region?) go forward.