EQ the DIs ?

It's right if it sounds good. I never filter any DI, I do the filtering or eq after the distortion because I want the amp to get all the frequencies from the DI but it's totally fine to eq the raw DI if you want to achieve certain sound, like the old misha sound that had a boost on the mids of the DI
 
I like to cut or boost a *tiny bit* in the low mids and/or hi mids, depending on if the guitar sounds scratchy, muddy, flat or could use a bit more bite.
Nothing really major, just a tiny bit already helps enough.
Mulitbandcomp, rarely, for the same kind of issues.

But it's really not the norm, only if I recognize that I can't adress a certain issue with dialing in the amp.

So I guess hipassing can work in some extremely boomy cases, why not, give it a shot.
 
sometimes a little waves rbass can work wonders on a di track before the amp ...
 
Working with a kind of djent band at the moment, using low tuning.
Before reamping, I tried to hi-pass the DI around 80-100 Hz with a very smooth slope (6dB/octave) to tighten the lows.
The amp reacts differently and the distortion is clearer ; doing this also prevent you from cranking the tone knob of a TS (like many does to reach this middy djent tone) and results in clearer mids.
But this works for a very specific tone, close to typical djent tones.

So yeah, I think there's no issue to try some EQ on Di's before reamping if needed, and I mean not only for djent tones.
If it sounds better at the end, that's OK.
Some ampsims even have HP/LP before the gain stages (like the new Wagner Sharp).

Sometimes I also use :
- SPL Transient designer for pussy pickers
- some kind of exciters to brighten old-strings DIs
 
Tim Pierce said in a Pensado's Place episode that he always eq's the DI when reamping.
I not 100% sure but I think he said that he added some high's to it..