chrkelly

Don't worry about having the fingerboard shaved, it's a perfectly standard procedure & part of any proper bass MOT. It'll play a million times better as a result. Get it to Thwaites and they'll tell you exactly what's happened & what's needed to put it right. It could be that the fingerboard has detached ever so slightly from the neck. It needs full contact with the fingerboard in order to be stiff enough to withstand the string tension. If there's a slight lift anywhere, the strings will bow the neck forward.

Don't risk it as is, could be very costly. If you're dead set on trying them, get the bass to a luthier & see if you could get a longer tail wire installed to reduce the after length.

Are they 3/4 Thomastiks? It shouldn't be a problem with the 4/4's or Pirastros unless there's some setup issue below the bridge, such as the tailpiece position/size.

What's the music, instrumentation? What do you want it to sound like? For the AI aspect how about something like Sonible Smart eq? I've not used it myself though. I like to keep things pretty simple, I only do jazz & classical - After checking all the phase, panning etc, I use mainly subtractive eq (if you can't hear something, it's usually because something else is masking it. Find the offending frequencies in the competing instrument & dip it slightly). The same with volumes, usually turn down, not up. Mainly wide EQ curves & usually never more than 3-4db max, I quite often find myself working in 0.25db increments. Don't solo channels often, there's usually little point eq'ing something when it's outside the mix. I usually record instruments in the same space so have to take into account the mic spill too. A good analyser will help you see what's going on. I don't compress unless it's for colour. I can keep volumes in check by fader riding, it sounds way more dynamic that way. I have a Varimu in the rack for mastering but it's usually for colour, set so the needles are barely moving. Reverb is your friend, learn how to use it properly. If your room is crap, I'd highly recommend some quality open back headphones combined with a good crossfeed plugin like Aspen Virtuoso. You'll make better decisions without your room acoustics fighting you. Always have a reference track loaded up to check with. Your ears become accustomed to small changes very quickly so have many many tea breaks to reset your ears!

Looks like a Marvin (https://marvinusa.com). Interesting concept but I've still never seen anyone use one.