The CMA he provided was really disturbing though...

Jason - The apathy is truly disturbing to me.

Doesn't disturb the neighbors

One consideration is that if the house is vacant, it's slightly easier to show as you're not disturbing the existing occupant.

However, despite that CC&R provision, the HOA (at least management) took the position that this was not an HOA issue (even though the entire neighborhood was disturbed), and that they are only responsible for common areas.

I would tell them to not disturb the owner/tenants. 

Most residential development in middle class neighborhoods has been “out of scale”, disturbing existing communities.

Many won't let you inspect the property and disturb tenants without such proof.

Is there any other way around it or would a non-disturbance agreement be easier to obtain from the mortgage servicer?

I certainly dont want to disturb the rent coming in, specially if I am cashflowing positive.