Here is my rundown of the feedback I received over the last months together with an analysis of the impact.
1. Remember the last action
this offers more possible behaviors:
1.1. Remember last action per record
be_user.uc.tx_news.1324.lastAction = SaveAndClose
This needs to be stored somewhere, thus bloating up the user settings too much.
1.2. Remember last action per table
be_user.uc.tx_news.lastAction = SaveAndClose
Same problem as 1.1.1 in case of a lot of record types being available in the system.
1.3. Remember last action for all records in one
be_user.uc.lastAction = SaveAndClose
Conceptual error: What happens if the last action is not available for the given type? Imaging news having "Save and New", while pages does not have this action.
2. Set a default action
2.1. Set central default action
See 1.3.1, what happens if that action is not available?
2.1. Set a default action per table.
3. Responsive Approach
The current idea is to show all buttons, based on the available screen width. So on a bigger screen all actions are available and once the space is not there anymore, it collapses down to the current splitbutton.
Another feedback we got regarding "auto-learning" buttons was that supporters did not like the idea because that would mean that every system looks different in terms of "Editors call us and they have a different button than I have".