If we perform an upgrade from version 5.4 to version eZ Platform/Enterprise 1.8 the URLs will not be valid (as in it will change).

The following URLTranslator is used on site.ini.append.php:

[URLTranslator]
TransformationGroup=urlalias_compat

And same goes for use of urlalias_iri.

There needs to be a way to configure this without re defining slug converter service, and there needs to be mention of this on upgrade guide