I never did understand [X] Route MIDI Clock. Now I do!
So it means “Route MIDI Beat Clock messages (MIDI Clock, MIDI Start, MIDI Stop, and MIDI Continue) from the selected hardware devices to the Cantabile Port, so that they can be monitored in Cantabile’s internal MIDI Monitor window and also transferred on Cantabile Routes” … or something like that …
With [X] Route MIDI Clock enabled the MIDI Beat Clock messages do show up in the MIDI Monitor with no issue …