Suitable Room Shape for Sonos Arc

I’m interested in buying an Arc but have a bit of an odd shaped room.  Starring at the tv, it has the following characteristics:

1.  To the left, a wall
2.  To the right, a 1.5ft lip beyond which is our open-to-above staircase
3.  Behind the couch (facing the tv) is 50% half-wall with a pillar, and the balance is open to the kitchen 
4. Ceiling- normal 9ft ceilings

This is obviously not ideal for virtual surround- but would it eliminate all surround and Atmos functionality?  Also, sound traveling in the direction of the staircase tends to amplify and become louder upstairs (see point 2)- would the side firing speakers contribute to this a great deal?  or would Sonos true play sense the lack of wall here (and behind the couch) and adjust accordingly?  Would it still be worth purchasing?

Thanks,

Zab