Purest, I don't see an issue (although since Support just said it can't be changed, the point is moot).
I default action is JUST like an action that has a button inline with the grid, but instead of requiring the user to click on the button to both select the record and run the process, they can click anywhere on the row. A much superior UI in my opinion. The default action can do anything a process does. Can run queries, open edit form, etc. etc.
Bruce