How to Use / Configure Workmail Remote User

I'm new to Workmail, but have configured and operated Exchange in the past. I have the Workmail Organization created, custom domain configured, and all is working. But I can not figure out the purpose / how to utilize the User "remote user" profile. I can create a user and give it the REMOTE_USER profile, but can not figure out how to tell Workmail what/where the remote mailbox is. For example, I'm assuming the "Remote User" is intended to be the same as an Exchange Remote User, in which case, I would want to tell Workmail that the username (e.g., remote-user) mailbox is hosted by a different Workmail Organization, or an Exchange system. Ultimately, what I'm trying to do is "redirect" any mail sent to "remote-test@my-domain.awsapps.com" to "real-user@gmail.com".

Yes, I can create a "full user mailbox" and do a forwarding rule -- the problem is that the original sender is not the "reply to." So I'm trying to figure out if this "remote user" profile would do this?

Or, am I supposed to (somehow?) create an INBOUND rule in the Organization for any email coming to "remote-test@my-domain.awsapps.com" that forwards to the external "real-user@gmail.com" -- which I can't see how in the INBOUND rules configuration of the Organzation.... ?

Thank you for any experiences or recommendations!

The only documentation I can find is -- "User created and enabled with a REMOTE_USER role is listed in the address book but do not get a mailbox in Amazon WorkMail. The REMOTE_USER can have the mailbox hosted outside Amazon WorkMail but will still be listed as any other user with mailbox in the Amazon WorkMail address book and can look up each others calendar to find free or busy information." https://docs.aws.amazon.com/pdfs/workmail/latest/adminguide/workmail-ag.pdf