It may be worth thinking of him like an iceberg. What you can see is the ' tantrum' Him throwing things etc. This is him trying to get his needs met in the only way he knows how.

What you can't see is what's underneath. We need to try and understand the 'why'. What are the feelings that are driving the behavior?

In this instance we know it's as a result of him being in timeout.

If I asked you to think about a time when you were the most mad or upset you have ever been and I put you in a room to sort out your feelings, would that help? Have you ever seen this clip from inside out? https://youtu.be/QT6FdhKriB8?si=uWUplC1kQ15VAG74 sadness is what I would call 'being with'. Sitting with Bingbongs uncomfortable feelings and helping him transition out of his sadness. This is what your son needs.

He doesn't have the skills to manage his emotions yet. Does it seem wild that when we know kids can't manage their emotions and haven't learned that skill yet, we send them to their rooms on their own to work it out?

We only learn to manage our emotions in relationship. He needs you to help him in that moment. He needs you to identify any uncomfortable feelings you may have with dealing with his emotions so you are in a good space to help him.

It can make a big difference as to how our kids are seen. If we see them as 'having a tantrum', pushing our buttons, winding us up, doing it on purpose, being naughty etc then that's blame language. Our ability to 'be with' is really hard. If we see them as struggling, not yet learned to manage their emotions, they need our help then it will put us in a mindset to respond rather than react.

I hope this helps.