We use a number of NDI encoders, including the BirdDog Flex 4k. It features a nice 360-degree tally light, but there isn't a great way to mount it to cameras, espcecially when a teleprompter is in the way.
We designed and fabricated a custom bracket that mounts to standard 15mm camera rods. Positioning can be adjusted with rotating knobs.
Fabricated out of PLA with headed thread inserts and billet aluminum rotating tightening knobs.