Sorry I'm here again asking for parenting tips because I have no clue what is and isn't reasonable and I have no one else to ask. 
I have 2 teens, one nearly 14 and once nearly 16, the nearly 16 yr old is developmentally delayed so probably has an age of about 12/13.
They have no ability to self regulate and if left to their own devices they'll literally spend 24/7 on Minecraft, Roblox or Xbox WWE.
They're not allowed Fortnite after they started getting incredibly and disturbing in their choice of language.
They both have mobiles and we have a family Xbox and PlayStation/Switch etc. All have really tight parental controls on.
We obviously need to think about loosening these especially when DS hits 16 bit I don't know how much to be taking in the development delay, he's being assessed for ASD so I don't know if I can access guidance then.
Both of them have little to no friendships (DS2 has more than DS1) and both won't leave the house unless made to.
I don't know what to do, they've always had the same restrictions despite different ages as DS2 acts more mature than DS1.
I need to find balance between encouraging time out the house, getting a social life and school work but also have age appropriate screen time.