They fundamentally solve the Topo-Naming-Problem I propose to try again after the next release.

I'm not super familiar with that problem, as it has been a minute. But I might try to give it another go at some point.

I don`t know the #Onsel fork. In what way does it differ from #Freecad or Freecad from #realthunder?

From a user perspective, it has a much more friendly UI in my opinion. When you click on an object, it displays a list of all possible actions you can take with said object. That to me was a huge upgrade over the base FreeCad implementation.