GreXXL it is incompatible with a lot of extensions that offer this type of guest interface. If you thr setting to force redirect is enabled. The extension assumes there is an intention to keep community content private. So it blocks off forum and api requests apart from auth.
I usually add the obvious routes from extensions that should be excluded (like fof oauth) but the user exclusions setting exists to allow further allowing by the admin.
I remember why the input for that accepts route names rather than a path. Paths do not differentiate between GET and POST and other types of requests. Whereas a route name is precise.
I wonder how difficult it would be to build a route selection component. That way options are visible.