@scooke No problem 🙂 It's quite confusing because I have been leaving various bits of progress all over this forum in various places...
Just to give an update on the current status. I have gotten synapse published. I put some initial docs at https://cloudron.io/documentation/apps/synapse/ (reading that now, there seems to a big wall of text. I have to simplify it). I am publishing riot now.
But both the apps require Cloudron 5.1.4 which is now going through our CI. In 5.1.4, we have a way to add .well-known docs which is required for synapse/riot to work. Hopefully, we should be in a releasable state tomorrow.