I totally get it. I wish fcpx would read the tc too. It would make life easier. In later builds of the Sony camera firmware, you can at least set the option to name clips to camera reel and date format which helps to keep clip names unique, which helps keeping track of the clips.
The method you suggest of reimporting all media and replacing all media in fcpx can work. It’s going to take a long time. I would suggest creating a new library, importing the media there, and work with your final timeline there. It will cause less confusion with older versions of timelines and media
Importing clips in to Davinci will also not be easy or quick. But the tc will match between fcpx and Davinci, which makes tracking changes easier.