Another pop up to deal with? Can this be put behind a preference guard (`interface.warn_on_replace_in_session` in various)?
* Do people *really* "accidentally" click the button, or is it intentional and they change their minds? A new popup won't necessarily change the outcome of intentional actions. * Popups like that just train people to click accept/press return twice/etc. So may not even help true accidents. * The change is saved in the undo buffer, so easy to back out.