okay, I think I have accidentally found the perfect game engine for 3DGS refugees: Xenko https://xenko.com . Free for individuals, uses C#, its editor is called as Game Studio and objects are called as entities , and you can use 3DGS entity action styled updates (see Asynchronous scripts) : http://doc.xenko.com/latest/en/manual/scripts/types-of-script.html (it is WIP, a lot of features are missing, so imo not a real option currently)
, and you can use 3DGS entity action styled updates (see Asynchronous scripts) 
