Wife went out and bought me a present

Say what? Is this universal, or just for one particular brand or manufacturer?

We've been looking at them on & off for a year or so, to replace our J.D. lawn/garden tractor, but this would be a deal breaker for us.

(Edit: Now that I think about it, since the steering is hydraulic, I guess this makes sense. But the brakes?)
On my Toro Titan when the engine is not running the hydraulic trans axles are locked up. If I lose power while cutting this beast will not move. In order to push it around the garage there are spring leavers that have to be un-latched to free up the axles. Go out and try pushing your Scag without starting and you will see what I mean.