Found a pretty nice universal remote to replace our Apple TV remote. But, it’s not quite perfect. Biggest hurdle is figuring out if it’s possible to program the volume buttons to control the HomePod volume while it’s set as the audio output.
It almost certainly would work that way, but I’m not sure the Apple TV has IR codes for volume up and down. I attempted to “learn” them from the Siri remote, but it seems to be sending the volume button presses over the network or Bluetooth.