Assuming that you,and others,are correct to believe that we (and the Japanese) are capable of doing so I wonder if it wouldn't be wise to do so...at least once...to send several messages to the Norks and the Chinese.
Of course Japan would have good reason to do so because they would want to send a message to the Norks seperate from ours.
And yes,tracking the trajectory would make sense for several reasons.
But imagine us (or Japan) shooting down one of his missiles with video proof provided to all major news outlets worldwide.The result would be amazing!
If we were dealing with an otherwise sane actor in NK I’d say yes. He would quickly read between the lines and stand down. But we’re dealing with a Godless psychopath who thinks he’s unstoppable.
We are going to have to take him, his top leadership and all is institutional memory out to solve this problem.
We know this. But if it can be done without revealing capabilities we’d rather not put on display unnecessarily.
After all that tech was built with a war with China or Russia in mind.