You might check what the agreement between the utility and the public utility commission is to see if you can have the PUC lean on the utility to provide the data you need.
I've had several meetings with a District Rep, who contacted his government rep at the utility for the area, who leaned into them. They said they would contact me; 3 times, and never did.
$7/ft is more than you should be paying. Get some more competing quotes.
I'd be very surprised if you can hit $30-40k per mile all in when microtrenching.