My 2 cts

First-whichever, the 12 or 16r, I'd go w/the even-row setup. Either 12/24 or 16/32. It requires that you reset markers and slide tractor drawbar pin-hole over 7.5" (usually holes in db slide work out right) for bean planting. You gain an extra 15" of planting and this will also move your tractor tires off dead-center from where the planter is trying to plant beans. Your openers will now fall 7.5" on either side of dead ctr on tractor tire. That extra row costs about $1,000 new, but it turns out being the cheapest row if you figure over all cost of planter. If planter doesn't presently have it-you can modify it. Unless the guy that builds the 3pt hitch conversion for Kinze has changed, his setup does (did?) not allow that. He couldn't slide the 3pt. Maybe that's changed-my apologies if so.

You are right about rear end of Kinze dragging in transport mode in 16r config. It seems that when we levelled the planter as manual describes for planting-you do end up w/"tail-low" transport. This was never a problem for us. It could drag the last carrying wheel (not transport) if you went thru a steep road ditch or culvert. The tire could drag sideways-this was a very remote situation for us. I suppose you could hit hard enough to do damage-we never did. That was not a problem w/the 12r planter....it was shorter & not so magnified. This situation would be solved w/the 3pt hitch conversion (not Kinze supplied), but again-you'd lose ability to shove over 7.5" for 16/32 config-again, maybe that's rectified now.

The Kinzes are narrower transport ASSUMING you don't need insecticide attachments. We do up here (NE IL) and they make planter wider.

Good luck