That combo does well in both my 280 Rems (1/2") and fairly well in one "picky" 280ai.Never tried Superperformance but many of the powders in that burn range (around 4350's) seem to be versatile. Part of me thinks it would be a good match for 140 grain class bullets in 280ai.
What performance difference did you see between IMR4831 and H4831? I'm getting ready to try out H4831SC with Nosler 160 Accubond in my Weatherby 24" Backcountry 280AI.
I prefer 7828 and Re23 because I try to squeeze as much performance/speed out as I can. None are Weatherby brand, but if your Weatherby likes the 160NAB bullets you should do well.