Best way to get Apple hi-res to Node

As much as I love the tight integration of Tidal within the BluOS app, Apple does a way better job (for me) recommeding new artists based on what music I like listening to. Currently I have an AirPort express connected to my Node 2 - I am using the optical input, since I figure the DAC in the Node is superior to the DAC in the AirPort Express. I was using the analog output from the Express, but figured it had been tainted by an inferior DAC prior to going to the Node ... perhaps this was pointless, I don't know. Anyway, given AirPlay does not support Hi-res, what is the best way to get Apple Hi-Res to a Node without connecting an iOS device, or is it even possible? I do have an older iMac in use close by ...