Web Services Management changes and installation improvements?

I just got a RaX80
After setting it up, I went to the remote management page
wow.
Only always Use https to access Router can be checked
Since the R7000, the port settings and limited access settings have disappeared

Checking the community article, this seems to be an "unfinished improvement" in the new firmware update

Because when installing the Rax80, he did not ask me to use the APP installation "throughout" or to bind the Rax80 to the APP account "on the local network".

Currently, it seems that the only way to access from a remote location is through the app, or by placing a computer on the local network.

There is no official explanation
a. How to set up or bind the account when there are multiple routers?
b. Do you have to remove the machine when selling or transferring it?