@ase I was looking at the release notes for the RouterLibrary. Am I right that there are no breaking changes, unless you are using some really weird characters in your paths?
The (potentially) breaking change is that trailing slash used to be discarded, ie lib-router.get('myurl/') was treated like lib-router.get('myurl'). This is now fixed and you can have two different handlers for lib-router.get('myurl/') and lib-router.get('myurl').