According to the docs the Vue Router is unsupported and we have to wait for the team to resolve the issue.
Looking at the git history for the page, the Vue Router was first supported, then experimental and then unsupported, without ever explaining what the issue was or is. Furthermore there is no link to the issue anywhere, which makes it a bit hard to keep track of.
Could you please elaborate on why it's unsupported? It would make it easier how to handle the limitation. It might also help someone else figuring out a solution to the problem.

We're currently in the process of starting a project requiring code sharing between the web and native apps and we would really really like to use the Vue router and not reinvent routing for our entire app because the NativeScript version of it doesn't support the router.