yeah, userpage discussion list only shows who started it, but the last post avatar extension shows avatar if there is a reply, i think its best to disable it for that page only if its possible.
for example second discussion last replier is somebody else but it still shows the original poster avatar.
![](https://i.ibb.co/0KWG2Y4/Ekran-g-r-nt-s-2023-03-14-235037.png)