Pretty good summary, imho, thanks for posting. I agree SAF is a publicity stunt. There is no way it will ever keep all aerospace airborne, replacing fossil fuels, in my "professional" opinion. Even if it could, we would be supplying it by means that would defeat the purpose, because it all came from extracted energy in any case. It brings back to mind Brazil's experience of trying to replace fossil fuels for cars by bio-fuels, again something cynically encouraged by the fossil fuels industry because they knew it would never work.
Only domestic and community hydrogen will replace fossil fuels. Notice every KWhr of solar energy stored like this is a KWhr less to heat the planet by the sun, and a KWhr that has been returned to the planet as a form of stored energy, to replace a fossil fuel one, taken out previously by consumers, converted to heat.
Notice also GeoEngineering would kill any chance of achieving this, the only real solution to stopping our destructive, heating existence, turning it round to instead a creative, cooling existence.
It does irk me a little this does not seem to stick with you Mike, who have so much good to say about most things, this is the most important one, the big one. Fix this and everything else is fixed.
Big aerospace should start subsidising efforts to make it happen also.