Probably one of the Holo Red users can tell best. There are a few pictures over on those threads. For example, search for I2S in and/or ask in: Holo Red impressions - Network Audio - PS Audio
Just googling a bit, I saw from an Audiophile Style thread the comment that the standard Topping setting should be the PS Audio setting.
From experience, if you have SACD DSD files, one thing to check is that the left and right channels are correct in playback. Just compare with a track with strong left vs right aspects, like the opening for Bowie’s Golden Years, with another source chain.