Have to kick FG. No guarantee you get a TD even if converting so you could still end up with 3. In the 4th quarter you also HAVE to go up 2 scores in that spot. Optimal.
They really need to work in some misdirection in 3rd/4th and short. I'll never understand why they never challenge the edge with Fields. With a better play caller, the Bears would be unstoppable in that situation.