You can do this already. It's just not particularly intuitive. You must first create and save the Action, then go open the Action. It will open in a fly-out window on the right, where you will see the Custom Fields/Attributes Tile for that Action. You can also go to a full screen view of the Action Record.
Don't know how new it is that you can ADD Attributes to Actions, but I believe they've been viewable (if entered in 7) for some time now.
You can do this already. It's just not particularly intuitive. You must first create and save the Action, then go open the Action. It will open in a fly-out window on the right, where you will see the Custom Fields/Attributes Tile for that Action. You can also go to a full screen view of the Action Record.
Don't know how new it is that you can ADD Attributes to Actions, but I believe they've been viewable (if entered in 7) for some time now.