Correct Jeff, if you leave the pin out of the 3rd row you'll still have the extreme "all the way up" position, then your next position is against the glass. Unless you had the hatch open then it'll go down until it rests on the tail gate. Or, put the pin back in as you say, after you've swapped the gears and it will be like you were never in there.
But now that you got me thinking about it, I wonder if you could just leave the gear out of the 3rd row, then your only position would be the "back" one against the pin. That would actually be an upgrade in itself... might be worth a try? Unless you want your kids to sit up straight.