Is it necessary to re-calibrate the DLS 2 when switching between MicaSense Sensors on the same drone?

While changing the camera will change the magnetic fields around the DLS 2, depending on the integration, those changes may be negligible. One way to test this would be to power on with camera A, perform a mag cal, and verify that all headings look good (at least check 0°, 90°, 180°, and 270°). Then switch camera A out for camera B, and check the headings in the same way to make sure that it still reads the same. To ensure repeat measurements are the same, it can be helpful to have a piece of wood (or some other non-magnetic surface) with lines for aligning the drone in four or more directions, at which point you can simply compare headings for a given rotation on the surface.