Depreciation Warning with Path in Mailer

I understand the reasoning behind warning people they shouldn’t be using relative paths in mailers, but for some use cases it actually makes sense to use them. One application I’m working on has a lot of logic around subdomains, so we pass the path into a helper method with some options, and it creates the full URL. This helper method is used in more than just our mailer.

Am I doing something wrong, or am I just using a smaller use case and should just ignore the warning?