A conduit would be my preferred choice, with separate shielded cables for T and R sides on all circuits.

If that's a no-go, then a bunch of shielded cables all the way through, with no mid-point punchdowns.

With the second option you still might have to get AT&T to adjust the LBO.

My $0.02 only...

Good luck.

"...Time moves slowly and it goes so fast..."

(Sandy Denny)