i just did an upgrade for my installation from 1.48 to 1.54. Snapcast playback still works, but the snapcast control in RompR is no longer accessible. My snapcast installation has HTTP/jsonrpc enabled, but RompR states that the snapcast server isnt rechable. So i did some digging - the outcome is kind of unique to my setup, and not neccesarily a bug.
I understand that for versions > 1.48, calls to snapcast are handled directly from the browser via js/websockets. Previously, snapcast calls were made server-side. This breaks setups where the snapcast webservice is not accessible directly from the client - for example when RompR is exposed externally via a reverse proxy, but snapcast isnt (or just listens to localhost). There are ways around that by exposing snapcast websockets externally, but perhaps there is a more elegant solution to that.
The other issue i've encountered is that when RompR is served securely via SSL/TLS enabled webserver, connectivity to snapcast is denied by browsers, because the websocket connection is not secured (ws:// instead of wss://). In the browser JS console, the exception "Uncaught (in promise) DOMException: The operation is insecure." is shown.
I hope this makes sense.