So I came here because when I tried to use middle mouse button (to set a filter) in the main inventory, I got a message that stated:
"It's not yet possible to set filter in the main inventory now.If you think you would like this feature, let us know."
Here I am letting you know.

I hope this will get implemented because I like a sorted inventory but I really don't like how the autosort does it, I want to be able to choose where everything goes.
Factorio is awesome, have fun playing everyone
~Airtheon