It would be great if we could upload our own certificate so customers can see portal.customername.com and still use SSL.
Nice! The feature you requested is being reviewed by our product team. We’ll keep an eye on the number of votes, and let you know if a decision is reached to implement. Thank you for being a partner in our process!
Or at least have Atera's back end generate one using free LetsEncrypt SSL certificates. Pretty easy to implement.