Jimmy, I use a program called "freesa" on my computer. I found it here on tb by a guy analyzing his swr grandprix. I use the ext.amp output on the back of my svt into the computer, while there is a cab plugged in of course. There is a very "slight" dip in the mids but, as you say, more of a slight boost in the low mids. For all purposes the svt is pretty much flat. I feel that the power section adds alot of lows somewhere or maybe it's just that the supere deep lows are not filtered out like ss amps. I run mine with the low cut engaged by the way. It sounds tighter to me. When I boost the 3k slightly, the amp scopes super flat. Through a cab it's not very noticable.
So, Jimmy, you have very good ears. That LMII is a pretty cool amp, I just didn't like the eq centers at all when I owned one. I foolishly sold my sansamp VT Bass and will be buying one again soon but, I'll bet that would sound good in front of the markbass head.