https://github.com/WeAreROLI/JUCE/commit/2e51654958df26d9c374e961758180cc842e0dfa
This commit should address the issues using an UndoManager with an AudioProcessorValueTreeState.
- An undoable action is no longer pushed onto the stack when the plug-in is loaded
- Redoing actions works correctly
- New transactions are started when you interact with an attachment
Since this alters the behaviour of the UndoManager this is technically a breaking change, but I doubt anyone was relying upon the old way of doing things.