While everything discussed here is done, there's some testing and detail work to be done for this, which has become Composr's new "Resource-FS" system. This is going to be finished in the next few days, but I'll put down here for reference...

Do a search of a Resource-FS hook's structure if it fails to look up a label, to confirm it really is missing - but only if we don't have too much of that content type (i.e. a safeguard)
Unit tests for resource-fs, life-cycle each resource type with lots of asserts (partially done, 'delete' ops not yet fully passing)
Unit tests for aggregate content types (ACT), life-cycling
Test ACT UI
Test ACT in detail
"Explicit move flag" used for Wiki+ page path, as currently prevents multi-categorisation of pages
Make sure GUIDs are explicitly set/specified for the resources auto-created when a match failed (currently it's not done)
Implement _folder.xml

^ all done