Will give it a try. Isn’t that essentially what the battery saver mode on Windows does, or no?
On my system at least, battery saver mode is a little weird. It's very aggressive with processor throttling (It usually stays around 1.1 ghz), making things a bit sluggish, but then occasionally I get spikes to 2 ghz when doing nothing taxing for the CPU. Throttlestop will essentially throttle your processor to its max non-turbo frequence (1.5 ghz on my device). So there are differences between the two modes on a SP7, but I have never tested it on a Surface Book.