Btw, i tryed to find such category and failed )
I think UI is the one of the most important parts of the game.
Your grammar and reasoning may be bad, but that’s actually a good idea.
If Slate was a separate category on the forum, it might incentivize community members to make community tutorials and help threads. It would indirectly help with Slate’s lack of documentation.
Anything that would improve the slate expierience would be highly appreciated 
I agree, this could be quite handy. UMG/UI kind of sits in an awkward category between Programming, Art and Blueprints.