Network access by domain name and reverse DNS?

I’m using a heroku server, and a mongodb atlas database. To make it work I have to open my Network Access to the world -

I have brought this up before, but I’m bringing up a new server and so I’m bringing it up again.

  1. I wish mongo would let me configure a domain name in my network access list, and when my server tries to connect, atlas would do a revers dns lookup on the configured domain name and validate it.
  • 0r -
  1. Could there be some api my server access to tell atlas to reverse lookup a preconfigured domain name, and then return when atlass is ready for my server to connect?

  2. Are there any ideas on how to secure connecting to mongo adlas from a server, that doesn’t have a fixed IP address because we aren’t paying for that.

It just seems like security is important and we should keep making things more secure.