2nd TAF did not operate mixed grps of Spitfires within squadrons. They operated either XVIs or IXs, not both.
443 RCAF and others operated standard tipped XVIs alongside clipped XVIs.
Wether the XVIs were "produced" clipped is a moot point, wingtips were modifed (on or off) at the squadron level, so on actual operations, they could be either.
...was going to add the reason why they did not mix IXs and XVIs was because the Packard Merlins on the XVIs were built to metric standards, and the tools needed to service the engines were different than the IXs. Also, many parts were not interchangeable, screw sizes were different (metric and imperial), ect.