I believe they asked about 100 octane only because it’s widely recognized that the other lower-octane fuels (Mogas,94UL, …) have all been introduced quite successfully for the lower horsepower engines. No issues there. The issues are for the higher horsepower engines where those other fuels won’t work, and for which there’s been a real challenge in coming up with a fuel that has the right anti-detonation properties, while also being compatible with all the materials it touches (o-rings, tank sealant, hoses, diaphragms, paint, …) Hopefully GAMI fuel will prove to do all of this, but there are concerns being raised among early adopters so getting the market feedback quickly is important, and also determining how pervasive this feedback is (outlyer, or major issue). My sense is that’s what AOPA is trying to understand so they can help separate facts from anecdote and get to a good unleaded, high octane option for the industry…