What mic was used in the process of getting that Engl Ironball tone you loved so much? I'm guessing none. Are you comparing the sound of a straight guitar cab to one that is mic'd? Two completely different animals if so. Mic's do their own thing to guitar tones.
I am not sure I get your remark.
I use to run
guitar -> Kemper (cabs off, EVH 5150 III profile, poweramp off) -> Engl Ironball poweramp -> cabinet
and now I am trying to go
guitar -> Kemper (cabs off, EVH 5150 III profile, poweramp on) -> cabinet
in such a way that the new tone is as close as possible to the old one. This of course mean modifying the profile to better incorporate the sonic signature of the Ironball's poweramp.
But since the cab section is off, I don't see where the mics should play a role
Some people do, and that's totally fine
I might be one of them I just spent a few hours profiling my Engl, and as close as it got - and it pretty darn close, jesus! - it always feels like some of the body and roundness of the tube poweramp is not there yet. Argh
EDIT: of course I can't exclude the "missing sth" isn't the DI box's fault...