Thanks for all of the replies. I don't have much seat time on this bike. My SOP when I buy an older lightly used BMW is to strip it to the frame and do a baseline maintenance checking the condition of everything. With bikes I have experience with, this is pretty much rote. But since, I am a brick virgin, I have been trying to better understand the "normal" watch and trouble points in order to hit as many as possible on this renewal so as to hopefully get the best result without going back in because I didn't know to do A or B.
With what time I have ridden the bike, I do get uncomfortably hot. When I am drafting a vehicle the temp goes up significantly but it does not show an overheat light. The right side heat deflectors under the fairing are missing, so I will fab some of those. For the cooling related part of the renewal, I plan to do the Johnny Blanket (c); replace all hoses; insulate the fuel lines; replace the fan with an aftermarket SPAL fan; install a fuel cooler; check the thermostat and water temp sensors; change all gaskets and o-rings; and clean/purge the entire system a couple of times with several rinses afterwards; refill with new 60/40. I have a new water pump and thermostat if they are needed after inspection.
So, with all that, I was just wondering whether there was any benefit to starting with a 3-row radiator since it would be cheap to do and the system would be opened up anyway. Concerned that I might be solving an imaginary problem or that it was even possible the newer 2-row rads are somehow more efficient than the older 3-row rads, I decided to consult the brain trust.