I don't think the rad would get enough air flow with only the hood/bumper slot left open - the rad only lives behind half that slot. (As you know.)
I was running @ 200-202 degrees F today (80 F ambient) with just my approx. 8x4 inch opening that you see in the pic in post 1. And those 24 square inches are right in front of the radiator.
If the electric fan is coming on at 205ish degrees, that's cutting it pretty close. And that's with me driving it very lightly. If I wasn't driving with load up some of the little hills today, I bet I would have triggered the fan by the top.