AirPlay 2 streaming to Sonos Beam (gen 1) + Play:1's (set up as rears in surround)

Hi there,

I recently bought a 2nd hand Beam (gen 1), which is connected to my TV via ARC. Besides an Apple TV, I also use Spotify Connect directly on the Beam and regularly use AirPlay 2 to stream audio from different Apple devices to the Beam. Everything works nicely, but I would like to take it up a notch by adding 2 rears to create a 5.0 surround system (preferably some 2nd hand Play:1s). Once the Play:1s are added as rear speakers, I understand that they will play ambient sounds (in case of stereo sources) or the specific channel signal (in case of Dolby Digital 5.1 sources) when watching TV (signals coming through the ARC connection), right?

Also, when I stream music through Spotify Connect right on the Beam (and the music option is set to “full”) they will act as a stereo pair and play the music together with the Beam, right?

Now my question is: with both Play:1s set up as rear speakers in the surround system, what happens if I use Airplay 2 to stream music to my Beam? I know that you can group non-AirPlay speakers with an AirPlay speaker to play AirPlay on all of them, but in my case I would not exactly group them (the non-AirPlay speakers would be configured as rears).

Could anybody please confirm that over AirPlay 2, the system would behave the same as with Spofity Connect (music playing “full” through both the Beam and the Play:1s)?

I would much rather get cheaper 2nd hand Play:1s than the more expensive Ones that seem to sound the same. Also, direct AirPlay to the Ones will be disabled anyways when configured as rears.

Thanks in advance and please let me know if I understood something wrong. :)

Regards,

Patrick