My ASD DD is now 17, and we went through such horrible times at that age. She was undiagnosed as well, didn’t start on the pathway to assesment until she was 14, and we finally got our diagnosis last week (“high functioning” .. a compete misnomer)
So, at that age, I thought I was dealing with a violent, rude & badly behaved teenager. I was a punchbag, her too was smashed up etc. It was through the process of diagnosis that I realised she wasn’t violent and rude by choice, she was a young person who was struggling to manage their emotions, having panic attacks / meltdowns.
Your child does not want to feel the way the do during a meltdown, it’s awful for them. This is not a choice - no punishment in the world will work, when they are like that. All you will do is make the whole situation more distressing for them, and for you.
Why remove their screen, if that’s what soothes them in this situation? Why punish them for an ASD meltdown? “Authoritarian parenting” will not work, it will only heighten the conflict.
What you could do is to try to talk to them, when they have calmed down. Find out what would help them when they are feeling out of control. Do they want to be left alone ? What is it they need. Don’t have this chat in a formal way, go into thier space, do something they enjoy, and bring it up in the conversation.
Parenting an ASD child is hard work, it’s important they know that you are on their side. Getting angry at them solved nothing, and makes it all wise.
The best thing I did was to access some support via a local charity, and did some “mindfulness parenting” - I remember them saying “if you always do what you have done in the past, why would you ever expect it to be different”.. this was so true, so I changed how I patenting. Less demands, more collaboration; less orders, more choice.