Thomas,
I am an Enscape user too; I also regret that currently Enscape versions doesn’t support relative paths.
Your way to fix the issue described by Norbert, seems to use a similar (or an extended ?) approach to that adopted by Julia Eneroth in her addon ‘Reference Manager’.
Further, shared parameters tables, global/local environment variables, …, could be used as complements to replace/extend automatic path rewrite when importing external asset/components.