Is it possible to use %user_uid_optional as a view path? I am using %user_uid_optional in the path of a view, but it doesn't seem to be working because the tab is not showing. It looks like that the user_uid_optional_to_arg function is not being called. Do you have any idea?
When declaring a views path, you can only use '%'.
This is because Menu API can't handle two loader functions in the same path, and Views already has its own (that loads the view itself).