Do I need to check the "My state (ME, MD, MA, NH, NJ, or WV) doesn't tax all of this interest" box for US Treasury Interest

[pricelin]

I'm entering a 1099 that has amounts on both lines 1 and 3. The amount on line 3, which is US Treasury interest, is not subject to state tax.

1. Should I check the "My state (ME, MD, MA, NH, NJ, or WV) doesn't tax all of this interest" box?

2. If so, why is that necessary? Doesn't Turbotax already "know" that box-3 interest is exempt from state tax?

3. If I do check that box, I assume I would select "New Jersey nontaxable interest, taxable to federal" from the resulting dropdown. But then how does that account for the fact that SOME but not ALL of the interest on this 1099 is federal tax free?

Thank you!