I ended up just using the impact. Less force on the column.

I MIGHT have swung it with a breaker bar - but would have really attempted this with a pair of 2nd hands holding the steering wheel. I was using quite a bit of force going in both directions - one trying to crack the nut while the other was holding the steering wheel. Enough to know that with the amount of force I was using, I would have preferred someone holding the steering wheel even more...

I don't know what the dealer tech used to tighten the nut up. Regardless, I should presume/assume he would have used proper procedures and in theory proper torque with no red loctite, but eh, one should never assume right ?