It's not entirely what Dave is suggesting.He's suggesting the split button dropdown should have a checkmark to set the default behaviour of the button.
@Dave Page In that case it will contradict with Save and Save As. Save As here is an extension of the menu and not the behavioural option.
I don't think it contradicts. Open vs. Open In new Tab is, for the most part, a choice that most users will generally build into their workflow, whereas Save vs. Save As choices will more commonly depend on the situation I believe.
In other words, I'm more likely to select the Open behaviour I prefer, and use it all the time, but the Save behaviour is dependent on what I'm doing at the time.
And what about recent files? We're going to add that as well in future.