Sonos Playbar and Play 1 surround to Arc Ultra

I have the Sonos Playbar which I’ve had for years and have it paired with two Play:1s for surround, as well as the original Sub.

I’m running into issues with the optical cable and its limitations.

Would my Play 1s work well as surrounds with the Arc Ultra?

Is there any reason to upgrade my Sub? Welcome any advice, thank you!