So, a quick update: BL5s and BS Core are working fine by powerlink. I notice no audio issues at all. I’m using a standard RJ45 to 8 pin converter and my old mk3 cables.
I’ve also linked my NAD M50.2 via optical to the core for streaming with Tidal. The combination is perfect...I get the first MQA unfold through the M50.2 and the core automatically detects the connection, so speakers jump on and off with no clicks. Very happy.