Apple's A20 Pro shatters Geekbench 7 single-core record — 2nm chip beats desktop Intel Core i9 and AMD Ryzen 9 by up to 32%
(www.tomshardware.com)
A20 Pro vs Intel Ultra 7 Series 3
I haven't checked what they do either, but I don't see that as a reasonable assumption.
If they test for short burst performance specifically then the short runtime is the point. You then use multiple iterations of the test run to get a reasonable, reproducible result by averaging.