my thought would be based on where your child is on the spectrum but in my own household
I use the stairs for "time out" Depending on the severity of the offence any were from 2-10 times up & down the stairs (all the way up & all the way down is one time) for more worse offences they get to clean the toilets in the house (if its a pretty bad offence then the toilet cleaning duties continue for a little longer)
for my autistic guy I use this less & more so
if he doesn't do what I ask (like hanging up his coat) or (tantrum about not getting a "cookie" or what have you) I will ask him if he needs to go "nite nite" & will of course say no or I will say "Ok No computer" "do you want no computer"
the computer is the biggest thing I take away if he's not doing what he's suppose to do.
the corner never worked for me he just didn't get it, he is one the low functioning side of autism yet in the past year he is finally vocal for communication. my mother use to make us run around the block if we were being to rambunctious

A meltdown is just a reaction to over stimulation and our kids really can't control this reaction, that said, I think a time out is a good idea not a punishment but just to let him wind down and relax call it quiet time and let him know hes not being punished he just has to calm down and that will help him feel better. I have my son lay down and take deep breaths while listening to soft music with the lights turned down. Just reading or looking at his favorite story book in a quiet place might help.

No wrong ️You doing it out of frustration but yes stop. Our kids don't behaved bad just because like "normal " kids it's also because of frustration. When He gets another trantum just sending to his room. I Know there is all his toys and tv but you don't want to punish him you want him to cool down. He will get out like nothing happened and you act the same.

I agree that a true time out which means going to his room or a place free of toys with a explanation that what he did was not acceptable in a true angry tantrum will show him that outbursts of anger wil not result in him getting what he wants, no means no and ASD kids need boundaries just as much as neurotypical kids. What some people that don't have chillden on the spectrum have trouble understanding is sometimes our kids due to sensory overload, will kind of short circuit in a sense, that they need to release this overwhelming feeling that has built up by just to much input, by tears, yelling sometimes, and in some cases aggression . Again this is completely different than just true anger and defiance for not getting thier way. Both issues need to be addressed and neutralized, but one with a stern talking to while the other with understanding and compassion ..

like that idea. i try to agow.my son that when he cant express himself or find the word is not to get upset but to stay calm if a meltdown. now i do use timeouts when he thinks if i cant get my way like for example take the dog out if he throws a fit because we told him now we give him a time because i want to show him that we dont act like that we dont throw fits to get what we want it important that he understand being okay when something doesnt go his way