vrecord settings / Desktop Video Setup mismatch causes dropped frames warning..

vrecord video and audio settings seem to override the BM Desktop Video Setup input settings but a mismatch does seem to cause a consistent Dropped Frames warning in capture_options.log like this:

DROPPED_FRAMES_TIMESTAMPS: 00:00:00.040 00:00:00.280

I don't see this a a major problem but it's disconcerting and not immediately obvious where the cause lies. We regularly swap between SDI / embedded and analogue / XLR inputs on one of our systems.