[Prof Yaffle]

I think the linking is specific to that tuner manufacturer, and is needed if you're accessing only one of them at one time, as both need to be active before everything works correctly. This commit seems to force the unused tuner to 'shadow' the used one and tune to the same services; I assume that using both of them for different services makes both active by definition so the bug doesn't then appear

I'd leave it disabled unless you're using that specific type of tuner - I certainly haven't had need to go anywhere near it with my USB tuners because each is a separate, discrete device.