Fantasizing about what might have been if the war in Europe continued past May of 1945 is not just a widespread hobby, but a profitable business. One of the vehicles frequently depicted laying waste to hordes of Allied tanks is the Panzerkampfwagen Panther mit 8,8 cm L/71 KwK 43, combining the firepower of a heavy tank and the mobility of a slightly less heavy tank. Yuri Pasholok wrote previously about how the gun, while technically fiting in the Schmalturm turret, didn't make the crew's life particularly pleasant. Let's take a look at a blueprint.
The quality of the original isn't great, so it might take a minute of squinting, but there are two issues that are immediately apparent.
One is that the commander's cupola overlaps the gun breech. As Pasholok points out, it would be incredibly uncomfortable to use it for observation, and using it would carry a risk of getting smacked by the gun when it recoiled. Interestingly enough, the commander's position on the Panther was one of the few stations that the British found acceptable in their inspection. Looks like that was about to disappear on the "improved" model.
The next problem is the loader's. The loader had a lot of issues in the larger Tiger II turret with this gun, so the smaller Schmalturm would not improve his lot in life. The blueprint helpfully includes the dimensions of a KwK 43 shell. In order to load it, the back of the shell would basically be scraping the back of the turret, which would make loading the gun even more difficult.