If he’s not climbing out then leave him in the crib!! It’s sooo much better to not deal with them getting up all the time. My son started climbing out of his crib at 23 months so we had no choice to convert to a toddler bed. It was rough. He was up all night for the first week. We tried so many different things but he wasn’t truly ready until several months later. My daughter on the other hand stayed in the crib til about 2.5, I think, and she had no issues converting. She never got up.

When they can fully sleep in a twin (or for those that use tot beds).

As soon as they start escaping out of it or they need more room. If not then I don’t see the harm in keeping them in a crib. So I think you’re fine.

We left our oldest in his until he was 4 because he never tried to climb out. By that time he was so big he touched on both ends.

As long as he's not Spiderman and climbing out I'd leave him in there for a while longer than go straight to a twin. SKIP a toddler bed ..it's not worth it.

I personally think there’s no reason to rush that. If he’s content I’d stick with it

I usually move them out around 3 but if he’s not ready and not climbing out I don’t see any reason to switch him

In my opinion up 3 years old is the limit.
My daugther was probably 2 1/2 when I switched her, she also liked her crib also didn’t climb out but I would find her lifting her leg over.