Hi @Jay_Kay - welcome! I don’t have an answer on when custom domains are coming back, but we do have a tutorial on how to set it up with a free Fastly account here: Community Testing: Glitch + Fastly TLS [Public] - Google Docs
This tutorial is part of our community testing program, so I encourage you to give all the feedback you can throw at us as we work towards bringing custom domains back in a way that’s more stable and easier to use.