My initial purpose to have that route is not related to imports. I would like to use example.com/123/456 (123 and 456 is arbitrary here as long as they are both [0-9]+) as a shortcut for example.com/tag/123-456 so it is not semantically “wrong” to use it.
However, the route doesn’t work for internal links (I need to refresh the website to make the route work), hence I need to detect each example.com/[0-9]+/[0-9]+ and change it to example.com/tag/[0-9]+-[0-9]+ which looks practically impossible to do without parsing each new post one by one.