Ring Doorbell Pro with 3 chimes wiring example clarification question

In the [diagrams](https://support.ring.com/hc/en-us/articles/360022454432-Wiring-Diagrams-for-Ring-Video-Doorbell-Pro-Setup) for "One Ring Video Doorbell Pro/one transformer/three internal doorbell chimes", there's no "Pro power kit" in sight but for the "One Ring Video Doorbell Pro/two internal doorbell chimes" there is a pro power kit shown. Is that intentional? Is there something about a 3rd chime that makes the pro power kit no longer necessary? Additional question: In both a 16v 30 VA transformer is recommended. Is there anything wrong with using a larger transformer (24v 40 VA)? In my experience with amps and DC electronics like phone chargers, the amp rating is the maximum current the power brick can provide, but I'm not sure if that's what the implication is with volt amps since they're more akin to watts than amps. Thanks!