How to remove event listeners in Firefox debugger?

It seems that right-clicking the element in the inspector, choosing "Edit as HTML" and modifying the html code (even as slighltly as adding a space after the code) makes the listener go away

The same feature is there from the inspector in Chrome, but as you say not in (newish) DevTools in Firefox.

Before DevTools, it was there in Firebug (screenshot), but the issue to port it across has been open for 3 years.