By the way, the reason I said not to use EQ above about 250Hz-300Hz is because the peaks and dips in that reason will start to be pretty small and closely spaced. The DEQ, having limited measurement resolution, can see a very sharp dip as something which is much wider and try to fill it in, when really it is not a wise thing to do, and vice versa.
If you are using an external measuring system like ETF then you can use EQ above 300Hz but I would still only suggest adjusting the general trend of things, don't work on any sharp peaks or dips.