(Old Idea actually, I could swear this used to work a few updates ago) - The maneuver in question : you shift-select a number of Tabs and drag them to form a new window. Strangely the result currently is only the active tab comes along to the new window - the other selected tabs are left behind.
Ideally the entire batch of selections is moved - I know there are ways of grouping etc. but those require more clicks and fuss, the simple - shift/ctl-select-drag gesture is about as effortless as it needs to be.