Please help with wiring new Wyze Sprinkler from Hunter Pro-C

Hoping to get a little help wiring my new Wyze Sprinkler that’s replacing my Hunter Pro-C.

First question: Is Wyze a worthy replacement for this Hunter? I just bought the house and hadn’t really looked at the sprinkler controller yet but wanted to have an online integrated controller and jumped on the Wyze Week discount. The Hunter looks to be a decent system, so now I’m questioning if this is a good replacement. I’m assuming it will be because I want the online/app/Alexa integrated functionality, so on to the real questions…

A. Looking at my diagram I think I have figured everything out except I have one brown wire (denoted with a purple rectangle) that isn’t connected to anything. It’s in the bundle of wires with the 1-4 terminal connections. Maybe it’s just an extra wire in the bundle or maybe there’s an entire zone not being controlled because the installer hadn’t bought the expansion 5-8 terminal connection piece and just said eff-it :man_shrugging:t2:. Should I connect it to terminal 5 in my Wyze and “see what happens”? :sweat_smile:

B. I noticed that there’s no wire connected to the Master Valve (denoted with a purple circle) and wondering if the unconnected that brown wire might go to an MV? Did it maybe just get accidentally ripped off at some point? Should I connect the brown wire to the MV instead of the terminal 5 and see what happens? :grimacing:

C. There are two sensor wires (denoted with a blue rectangle) and I don’t know how to tell which wire goes to the S1/S2 on the back of my Wyze and which one goes to the VAC(-). In my Hunter, the two terminals are both labeled “SEN” and that’s it. Am I correct thinking that one goes to S1 and the other to VAC(-) or is there another configuration like connecting one to the S1 and the other to the S2 and expect power to come from somewhere else? Again, how do I tell which one goes where?

Thank you so much for all your help!!!