Should work well.
If you can try to maintain the equilateral triangle between the centre of the love seat and the M80's.
And don't forget your sub would ideally be placed where it works best for the room.
And (lol) the 87.5°-90° position on the wall,inline with your ears, to the sides of the love seat)may also work for the QS8's. Slightly ahead of the 90° location can have an added benefit IME/IMO.