Steve, do you think a sort of cyclone with the air mixer valve added would work? I haven’t seen anything for that yet. It would produce a drag on the system but perhaps a flows oversized cyclone would account for that. This would be a way from the carb and connect via hose to prevent weight stress. That final cyclone may also help drop soot one last time before the carburetor.
Or maybe a mixing chamber before the hosing going to the carburetor. Like many using their truck air cleaners as a mixing bowl.
I think a small green propane bottle or something in that Liter size range could work, maybe.
Edit: It seems that the WW2 style of air mixing makes a lot of sense. Flows demand on different fluids. Either Air mandated or Gas mandated. Peep the pictures in the link.