Best way to discipline a teen. (Asd)

[Cheeeeislifenow]

Shamelessly posting for traffic. Son is 13, almost 14. has some very challenging behavior problems which are currently being addressed. But I am talking about the likes of general dis respect, when speaking to us, or Being nasty to younger brother and not taking responsibility.
He is not into tech so no phone, I pad etc. He does play one sport which he needs to play for regulation etc.
He does not care if we are "disappointed" in him. He does not care if we say no telly etc.
I know that punishment is not discipline but the reality is he is ending up with no consequences at all for doing or saying what he likes.
If I take away the one thing he likes Lego etc then I am not respecting his need for that as part if his ASD.
The result is an entitled, rude lazy teenager who does nothing for no one except himself and is disrespectful in every way to boot.
Any ideas on some new discipline strategies I can use. I am kind of at my wit's end to be honest.

Create firm boundaries for yourself by walking away and telling him you won't engage with disrespectful people. Stop doing stuff for him and leave whatever you're doing (for him) immediately and tell him you don't engage with ill mannered, disrespectful people.
Be stony faced about it.
He needs to learn that you have rights as does he.