The editWindowActions and extendedEditWindowActions frames do not contain any logic, you can look at them if you find edit-window.actions.xml and extended-edit-window.actions.xml descriptors respectively in the platform code. They are just bound to actions with predefined names windowCommit, windowCommitAndClose, windowClose. These actions are added to your editors by the EditorWindowDelegate class that is responsible for entity editor logic.
So you can change saving behavior of an editor screen only by overriding AbstractEditor methods such as postValidate(), preCommit(), postCommit() and others, see documentation on AbstractWindow and AbstractEditor and JavaDocs for details.
On the other hand, you can replace standard windowActions frames by any other visual elements like custom buttons and just assign predefined names to them. Binding of these buttons to standard actions will be done automatically:
<button id="windowCommit" action="windowCommit"/>
<button id="windowClose" action="windowClose"/>