CX9 offers no tether anchors in the 3rd row.
In terms of fitting seats in the 2nd, I only recall thinking that the front seats of the CX9 are very thick front to back, and sort of curve back at the top. Cushy and comfy I'm sure, but I recall thinking the front to back thickness of the seatback ate up some of the 2nd row front to back room. Hard to explain, I guess. It was in the context of installing a rf Advocate and mom having to lose some legroom to make things work. Normally parents can have their seat quite far back in terms of legroom as long as they agree to sit fairly upright, but in this instance simply sitting more upright didn't cut it. Deal breaker? No, but something I noticed and thought hmmm. Thick front seats, lol. Who knew.
If they need the drivers seat all the way back, the 2nd row middle seat of the Pilot is really friendly. They could put the KF there, and the Graco seat behind the passenger. Or vise versa, point being the middle seat is a 'real' seat - no hinges, narrowness or other things that normally create issues in other middle SUV seating positions. Pilot is just so .. friendly for car seats.