I ordered a TS 2 at 45.0, 1/2” below the new standard 45.5. It has the red +2 gram weight. Maybe it has to do with the location of the weight on the club head. I agree with your assumption, I thought you lost 3 swingweights for every 1/2 inch cut down. I think that usually equates to 6 grams of head weight needed to return to standard swing weight, but mine only has +2g.
I was going to order additional surefit weight to try it out on one of my shorter shafts, so I guess I will order a blue weight cause that shaft will play at 44.5. Golf shop told me I can order additional single surefit weights, but that would not be available til this December. Hope this helps!