Contextual menu item with something lime you mentioned "paste without trackers" would be a good and easy to implement solution as the function already exist in FF... Something called "Paste clean" or "Clean Paste" would/could also make sense
I must agree with everyone here - the issue is really bad but could be fixed by changing the sensitivity to the side swipe required to close a tab. It feels like it take alot more vertical motion to move thru tabs and so very very very little side mo...
