OnePlus said it ramps up when the demand is high, which hasn't been disproven that I have seen.
What we need is an unofficial, and therefore not detectable benchmark that puts out the sort of stress that OP claims triggers that.
That would I hope answer that either way.
Plus benchmarks aren't terribly useful with such small amounts between them.
A user isn't going to notice the difference between most of the results.
Plus they are only part of the picture, as other things such as responsiveness to touch, number and duration of animations in the UI etc all contribute to how quickly something happens.