If the wheels are outboard of the mowing deck, there's going to be an edging problem.
A couple of years ago, maybe here at th3core, I broached the idea of using some sort of stake system to use gps to triangulate & navigate the yard rather than perimeter wires. Of course, I didn't think about frequency restrictions. With current cheap tech, I think even the stake system is crude. You could easily teach a bot now and store the data onboard. Just put smartphone guts on it, then press record and drag it around. Maybe drop a few magnetic position markers so it could cross-check its positioning while mowing. And the setup needs some sort of rfid fairy dust that you could mark perimeters with. Another dust would mark direct trails back to the charger, etc.
<added>
And another pink, glittery dust for Gurtie's chickens