I’m not sure that the Ableton Link chop has ever really functioned the way the protocol intends, as its meant to send tempo/start/stop/sync data bidirectionally between all of the peers on the link network.
What the ableton chop actually seems to be doing, regardless of whether the undocumented, seemingly non-functional startstopsync parameter is enabled, is generate beat data from only the tempo coming from a peer, ignoring sync and stop/start messages, and with no ability to push data back to the link network.
While super powerful tools exist in TDAbleton that preclude the necessity for this functionality if one is only working with Ableton, for certain simple tempo integrations its overkill, and there are many other tools like VCV Rack, Resolume, tablet based synths and sequencers etc. that work with the protocol, can control each other bi-directionally, and can stop or start the network while maintaining sync. Any chance we might see a fully fledged abletonCHOP sometime in the future?