Yes that would be a good idea (actually this is something I’ve been wanting for a long time, see for example https://markmail.org/message/6cvm5hocvtbqtgp6 - It’s been discussed again last year I think too, would need to spend some time finding the reference to the discussion).
What would be important though is that it wouldn’t support the ability to unset a property (unless we introduce a special syntax)/ We would also need to handle the strategy for overwriting a map (for example the extension.oldflavors you mentioned - will it add a new item or remove it).
Have a good weekend.