If I was going to move to fiber (and I'm about to experiment), I think I'd keep an open mind about the relative merits of a switch. Some people (and I think
@audiobomber may be one, not sure), do use fiber but the last link in the audio chain before the DAC is a switch for its galvanic isolation. So the fiber does most of the heavy lifting as a noise killer and the switch is there to sweep up any noise which the converters may or may not generate. The switch may prove completely redundant of course (and I know you've already made your mind up here!) but I have one on hand so can compare with and without. WIll report back, though not sure how long it will take me to complete the experimentation.