I like the top picture better. But, like someone said above, we're limited to the view we get in these pictures.
You don't want to grind into the contact patch. But a tiny bit won't hurt too bad. The way these gears work, the contact between gears occurs on several teeth simultaneously. Furthermore, you don't use reverse as much as forward and rarely as much torque in reverse as in forward. So concentrate on saving the forward contact patch more than the reverse.
Cleanliness is your big concern now. You don't want metal filings in there when you're finished.