Every source I've seen says human hearing is most sensitive from either 1kHz or 2kHz up to 5kHz. So 4-10kHz might be where you feel you're especially sensitive, but it's mostly above the range where human hearing is generally most sensitive.
At any rate, here is the 8361a Klippel measurement from
@amirm 's review:
View attachment 402388
The energy from 4-10kHz is basically identical to the energy from about 300Hz to about 1500Hz. From 1500Hz to about 3200Hz the response looks to be a bit more choppy, to the tune of +/-1.5dB through that range as opposed to what looks to be about +/-0.5dB in the rest of the frequency ranges.
So I don't see a pattern, subtle or otherwise, that supports your claim. And as many folks have pointed out in other threads over the past couple of years, the 8351b's response is even slightly smoother.