The confusion over Denon / Marantz devices and their Roon Ready vs Tested status has been a bit of a saga.
The recently released firmware for several devices along with an updated HEOS app now allows several network players and (SA)CD players to be used with other RAAT enabled players . Works nicely - thank you!
Marantz have just announced a new streaming AMP the 60n which is shown as ROON ready by Marantz but not on the official ROON partner site.
Gives us a glimpse of the path forwards - though we are yet to see a multiple zone AVR listed as Roon Ready they seem to be focusing on new releases rather than older devices (such as the 40n) and maybe we will soon be pleasantly surprised and both of these will appear with appropriate firmware.