Okay, well I've seen a lot of PCB "patches" in my day. It's definitely do-able. I made one PCB in quantity 50, got a resistor in the wrong place and had to use an 1/8W through hole part to fix it because the leads helped me jump a gap. 
But all the boards were easily fixed that way.
Because the current set input is probably low impedance, it's a bad idea to connect them. It would only take a small offset to upset the balance. The effect is to make the current working state un-dependable. Changes in temperature, supply voltage, aging, and many other things could affect it in the future.
Not to rub salt in your wounds, but did not a little voice in your head go, "hmmm, is this really cool?" when you designed it that way? Since it's not covered in the data sheet or anywhere else?