This works for short recordings, but for longer recordings explicit continuous sync is needed, almost universally using Timecode, because normal quartz oscillat

This works for short recordings, but for longer recordings explicit continuous sync is needed, almost universally using Timecode, because normal quartz oscillators are not precise nor stable enough to guarantee single frame accurate sync over, say, an hour (which would be 10 ppm or so, 1/3600*30)