We've been lagging behind in updating, so I apologize for the tardiness. The following commit 7fc6286 causes any packages that were previously using a config/routes.php to create routes to break.
Reading the docs, perhaps this wasn't an intended feature in the first place?
I'm mostly making a comment here to make the maintainers aware of the change and leave a trail for others that may have the same issue.
Our current workaround is to use the package's bootstrap.php file to load the config and manually add it's routes to the Fuel Router:
// Load and register routes for this package
$package_routes = \Config::load(__DIR__.'/config/routes');
\Router::add($package_routes);
This does change the order that the routes are registered (package routes came after app routes before), which may which pattern matches first in the router?