with a view to conducting a non hermetic-saga also marked on magical research what types of breakthrough to misteries would be appropriate for hedge magicians?
Absolutely; I would love to run a Raudskinna Compact game based on that very idea but the Order of Suleiman certainly would support that style of play. AND that is if you need an outside organisation needed to provide a reason to bind the troupe together.
Heck, even folk witch covens has explicit reasons to do this sort of thing.