AR-1 and auto reversing a turnaround wye

[Puddlejumper]

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.

It is not a cure for bad design, it is to eliminate the necessity of manually throwing a switch to change polarity of the tail track. It is quite common in DCC applications for reversing loops, wyes, and turntables, and I see nothing wrong with it.

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.

Can you explain this further? I have never seen a reversing loop or wye that didn't need both rails gapped in 2 places. I also don't understand what you mean about railsync and using a separate booster for the tail track.