Definitely +1 for the IPv6 support! Some users of SYNCROOM from YAMAHA (
https://syncroom.yamaha.com/) in Japan have recently tested SonoBus. We found a lot of great potential in SonoBus, including versatile FX, multichannel support, and unlimited players in a group, but the overall experience was still better with SYNCROOM. This is partly because SYNCROOM supports IPv6, which is much less "crowded" than IPv4
(at least in Japan), and can thus provide lower latency. Thank you for your great work and we very much look forward to the future development of SonoBus.