preheat requirements for A992 2

Here's an excerpt of AWS D1.1-15 Table 3.3 (I assume this is what you were asking for):

Yep, that is it. I only have a very old AWS given that I do exclusively precast/prestressed concrete and that mostly uses small welds in single pass fillets and flare bevel so have not invested in a newer AWS but need to do some welding on 2" A992. I was assuming that it would be 150ºF like the other grade 50 steel but wanted to make sure.

Ok, time to split hairs.
Given an A992 beam with a 2.48" flange (W27x368) what preheat temperature should be called out?

Per table 3.3
1½" to 2½" inc. preheat to 150ºF
over 2½" preheat to 225ºF

So, by the book preheat to 150ºF. BUT... if it was 0.03" thicker, it would need to preheat to 225ºF. That is a mighty big change in temperature for a very little difference in thickness.

What say you, 150º, 225º or something in between?