Ive never heard of the Doherty Threshold, but looking it up, it seems that its actually saying > 400 ms "is painful", not that its "imperceptible". And that aligns with previous rules of thumb I've used for mobile UX -- you generally want things to be < 100ms, and ideally < 50ms. If something results from user interaction the bar is much closer to the 50ms side of the range.