I’m seeing if Roon can replace the Apple Music app. I tested by copying 21G, this took over 5 hours. I think I see the download stopping unless the app is in the foreground. Even then it’s painfully slow.
My core is a Mac Mini M1 connected over the house Ethernet (gigabit)
Files on the SSD
IPhone XS next to the WiFi router
Ping to the router from Core is <1ms