OP he sounds just like my DS who will turn 8 in a couple of weeks. He started having whopper meltdowns over everything around age 3. I think he has got a bit better at controlling himself over the last year or so, however just when I think he's been really calm for a good while, he will have a meltdown every day for a week, just to prove me wrong. Like you said, my DS can go from 0-60 in two seconds flat. He seems to FEEL everything very strongly. I also think he's a bit emotionally immature.
When he's in the middle of a rage, he can't hear me. There's no point in trying to reason or threaten while he's still angry. Getting angry or shouting at him just makes him worse. I try very hard to not react at all while it's happening. I take him to his room and now, eventually, he stays there and comes back when he's calmed down, which could take anything between 5 and 30 minutes. Punishments don't have much effect - when he's calm he listens and sees reason over whatever the issue was, but in the moment he loses control.
I've also had to learn to ignore reactions from others when he does this in public. I just have to take him somewhere quiet to calm down, e.g. the car. Not easy.
Some kids are just like this I think, and my DS is getting slowly better at controlling himself. If I do give him a consequence (more if he's done something deliberately naughty rather than just getting angry), he now accepts it once he's calm which is huge progress from before, when he would have a new meltdown whenever he remembered about the punishment.
We maintain quite strict boundaries and I do think it's paid off. One of my friends has a DS with similar rage-issues but her approach has been to walk on egg shells around him to stop a meltdown at any cost, and tbh he's getting worse and worse and the whole family is revolving aroung keeping him happy. I couldn't live like that. I do on the other hand give my DS responsibility for his meltdowns, e.g. when he had a big rage over doing homework, I did not get involved and left him to explain to his teacher why it was not finished.
Good luck!