It will be much easier without the switch. The Denon receivers LAN is always connected, when the receiver is on standby. And it’s power consumption in standby is nothing to worry about.
Then you can easily control it from HA whenever you want.
So, the switch in front of it is just overkill…
I have used a smart switch differently to save some power. All of other stuff around the receiver (DVD, PlayStation and such) are behind a switch, which gets activated, when the Denon powers on and deactivated, when receiver goes standby. That way the only instance consuming a minimal power is the receiver it self.
So yeah, it takes 1,5 W continuous, but the setup is never unavailable and ready to be operated from HA and startup is instant… 