Wiring a wye is not complicated. It's only a little bit more work than with a single turnout.
And the wiring schema as .pdf
Main routes are from A to B or A to C. You have to throw turnout No.1. Turnouts 2 and 3 are in normal position. The switch from turnout No.1 powers the frog of the crossing too! Therefore you need a DPDT. If you run A to C to have to throw turnout No.1 into reverse position. With the switch you change frog polarity AND the polarity of the two frogs of the crossing! Turnout 3 is in normal position.
If you want to run from B to C you need the correct polarity
at the crossing. Ok, you can use a Hex
frog juicer. But a simple switch is not so costly.
Therefore the turnout No.1 has to be in normal position for this route. Remember,
No.1 powers the crossing.
You change with the switch the polarity of the track power. You doesn't need to change the frog polarity! It's always the same.
But you have also to change the phase of the Loconet. You have to change the polarity of the two outer wires! If you do this not you will run into trouble at the next booster.