I comprehend your view that the Lord became a man for all time. However, I wonder if He can discorporate at will and function like a spirit (whatever form He used to have). What if Jesus resides mainly in human form but can voluntarily set it aside to do important work or something?
Jesus went to great lengths to demonstrate the fact that He has a tangible, physical body. He invited His disciples to touch Him and repeatedly ate in their presence. But it’s clear that His body has some capabilities we lack, such as suddenly appearing inside a locked room.
If this is what you mean, then the answer would be yes. But I don’t think He can simply go back to the way He was before He became a man. When we receive our resurrection bodies, we’ll have the capabilities He demonstrated, (1 John 3:2) but that doesn’t mean we’ll be just like God.