LM3485 current limiter (\$R_{adj}\$) value selection
So I finally got around to actually testing this. It turns out that the current protection kicks in at around 4.25 amps with a 39 kΩ resistor. That squares with my calculations more than it does TI's.

I'm not sure at this point whether I want to leave the protection that high (the circuit is rated for only 2A) to accommodate surge capacity or reduce it. But that's another question for another day.