"I wonder how many Green supporters (or would-be Gss), would bother about the GP changing from supporting Independence to some form of Federalism (in or out of the EU)."
Good question. Currently the Scottish Green party policy is independence, that was decided through a democratic debate and vote in the party. If that were to change, a similar process would need to happen.
My feeling is most Greens see independence as a means to an end, rather than the end itself. Personally, I'd be fine with proper federalism, others might disagree. I know some members don't agree with independence and may have voted No in 2014.
"I can only imagine rallies where the faithful turn out to cheer. "
Presumably with Oor Nicola receiving ten minute standing ovations and being all presidential.