Is there a fail-safe bypass relay in case the LM 26/44 power supply fails or a major fault is detected?
Yes, the relay defaults back to "no connection" state when power is lost or a PSU fault is detected.
On larger systems the LM is not normally the main matrix solution, but acts as part of the system. Therefore we often have another device monitoring the Lake system via the network and operating system using the 3rd party control protocol. Lake has a "heartbeat" and fault reporting system over the network that can be interrogated and form part of the EVAC compliant system. Many lake devices are used in DN54/BS/NFPA compliant EVAC systems.