Does anyone know if the russound ST2 (only) is capable of 2-way with the XP-8 with the RNet driver? I know I can tell the ST2 to which source each tuner belongs, but I don't know for sure if they're going to respond to the appropriate codes if it's not hooked up through a cav or cam

I'm going to guess yes although I haven't tried it, because the RNET protocol should be identical whatever device is spitting it out be it an ST2 or an ACA-E5. I believe the devices duplicate/forward all serial communications out all serial ports(RS232, RNET, Keypads, Etc) which is why you get the tuner metadata out of the CAV/CAM/Sphere's RS232 ports to begin with. I can confirm in a 1 way scenario you can send a 1 way command to any RNET device and it will get repeated until it reaches the device the string is intended for.

Guess I've got nothing left to do but just give it a go. I had really thought I saw the st2 in the pulldown list in the driver, but I guess not.

Joe is correct here. I've got a lot of experience with the russound Rnet/RS232 programming. Each RS232 port receives/sends the same data. You can control multiple controllers through through 1 RS232 port.

If you have two CAMs you can send C2 RS232 codes to the frist controller and it will send it via RNet to the second amp. This works for any RNet connected device in the setup. Whether it is the Sphere/CAM/CAV/ST's. Anything that has the RS232 can send commands to connected devices. (unless your using IR, to control everything because it's either IR or Rnet control).

The metadata is part of the RNet structure and as long as the driver works properly you shouldn't have any problems.