[Question] How much FoV overlap is required for successful stitching in a multi-device setup?

[firebaugh]

In the documentation provided for multi-device setup, specifically the demo documentation here, it reads that the devices should have "sufficient field-of-view overlap for reliable stitching."

Roughly how much field-of-view overlap is required between devices for reliable stitching?

It would be great to know a ballpark estimate of how much overlap is required and how many hfov degrees to expect to gain from using 2 or 3 devices.

Thanks!