Are you talking about audio delay to time align speakers in large areas?

I think my only real time delay concern with this project is the delay introduced by the Sonos system which I can't really do anything about because there's no way to delay the live acoustic sounds created by the piano.

The piano is in a Living Room that's about 40ft x 50ft and there's an adjacent Dining Room and then a Sun Room on the other side.  The floor plan is fairly open in this area, so I think when the piano is used as a music source the whole house audio in the Living Room, Dining Room and Sun Room will remain off because you'll be able to hear the piano clearly in these rooms.

The other rooms and outdoor areas where you might still be able to hear the piano are around 75-100ft away, so the 70ms Sonos delay might work out about right.  Other rooms/areas will be too far away to really hear the sound coming directly from the piano so the Sonos delay shouldn't matter.

Client approved the estimate yesterday so I'll let everyone know how it turns out.  Probably 2-3 weeks before I get it scheduled...