Help wiring 4 way switch

I have three connected switches I want to add Leviton smart switches to but the wiring seems weird to me. I’ve wired several three way smart switches but this is my first foray into four way. One of the switches has two blacks, a red, and a ground (with a neutral in the box), another switch has 2 reds, a black, a white and a ground (and neutral in the box), the final switch has a black, a red, a white and a ground all in the same romex (no other wires in the box).

I haven’t disconnected anything yet to test with my voltmeter so I don’t lose track of where things are connected. The second and third switches seem unusual to me. The wiring is about 15 years old, fwiw. Any tips for wiring this up with smart switches?

I think it is wired like this:
4-way light center wiring

I decided to not use the switch with a single 14-2 romex going to it and just wire it as a three way switch. The switch I omitted has a shallow box so I wouldn’t be able to fit a smart switch in there and the switches I have all require one more conductor than I have going to that box.

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