When adding properties in the Animation Window, properties are removed from the list of available properties. This works fine with Position and Scale properties, but the Rotation property is still in the list, even after adding it to the list of animated properties... it should no longer be listed in the Add Property browser list.

This was working as expected in 5.2
This is no longer working since 5.3 (regression)

Repro:
Create a Cube
Open AW and Create a clip, Save
Add Property... Position
Add Property... Rotation
Add Property... look at the list: both Rotation and Scale are still available
... only the Scale transform should be listed since Rotation is already added.