The real +ev move is probably just to let Jones walk (as much as I do like him) and not waste a salary on him. Back-up C is not an important slot, you have Len, you have Lyles/Metu who can be a small-ball 4/5 combo. If Queta floundered in the 12-15 MPG role, we have options. Honestly, Lyles/Metu as your back-up bigs is probably way better 90% of the time and you have Len for any real big big dudes.
Assuming he's looking for like a 2/10 deal or even the contract Len got. 2/6 is probably the max we should go.