Installing two Ring Wired Doorbell Plus with two existing doorbells and two chime devices

Hello, our home has two existing doorbells and two chime devices (plus the 16 V transformer attached to the circuit breaker box). Each of the two chime devices has *three* wires - Front (green), Transformer (white) and Rear (red). If I purchase two Wired Doorbell Plus units, will I need to add the Pro Power Kit to *both* chime devices? If so, would one attach to the Front + Transformer and other to the Rear + Transformer? Thank you very much.