Loading a scene is different to "normal" file readers (see T2646), so the usual file reader approach does not work.
If loading scenes should be possible via File/Open or Drag&Drop, the best place to implement it would be
These files are both part of CoreUI, so CoreUI would need a dependency to SceneSerialization. I guess this is not wanted.
Sascha, what is the current status of this command framework? Would it be useful for enhancing the File/Open possibilities?
I leave this open for discussion, because I cannot see the best way to do it yet.