AR-1 and auto reversing a turnaround wye

[Bahnmoeller]

In the case where the track between 2 turnouts is isolated that portion of track should be longer than the longest train you plan on turning on the wye.

With small wyes it will not work, as a train will in most cases be longer the any leg of the wye.
With very large wyes it will introduce unprototypical limitations, as no second engine is allowed to enter from the "west" while another is leaving to the "east". A situation quite common when there is much activity.

The auto-reverser will change the polarity of the rails instantly when the loco's leading wheelset bridges the gap.

An auto-reverser is no cure for bad design. Its like switching off the light by making a short.

Either arrangement will work, but I think the top one is more common.

And it is the better design. Put the gaps as close to the frog as possible, then nothing will cross both gaps at the same time as the usual prototypical care will prevent this.
Change the phase of the turnout and the tailtrack with an switch together with the mechanics. Depending on the lenght of the tail I would recommend to change the railsyc only and use a separate booster for the tail and turnout.
BTW: The frog of this turnout is always on the same phase as outside rail of the opposite leg, so you need only 2 cuts.