Excellent. Haven't seen this solution before and have not seen any set up which allows both camber and castor adjustment.

Have you come up with ideas on how to ensure the rose joint can't undo itself from the top of the insert/rod? Loctite + Lock-nut maybe I guess. I know the bearing on top of the spring hat will help negate this but I expect there will still be a tendancy for it to try to work itself loose which would be a worry at speed.