having folders on my custom objects on my extension’s list would improve my productivity by a lot.
I have custom objects inside custom objects inside custom objects inside custom objects that are on the scene, the list of custom objects in my extension is getting ridiculously long and it needs a way to better organize it.
Please. 
Have you consider using extensions as custom object folders?
Out of curiosity, do your objects contains events?
Doesn’t fit my system. And I would go back to the problem(problems(one of them being that thing with external variables that messed up my previous system forcing me to adapt into this new one, that could use folders)) that brought me into doing things this way.
Yes, most of them have events, and the ones that don’t are composed of various objects and being in a custom object sticks then together.
