Thanks, found it!
I removed the "if (iAdjustment > 4) iAdjustment = 4;" line, which should do the trick for what I want.
How would I go about recompiling everything with this new change included? I'll be trying to find this out myself after I post this, but if it's possible to say in a few sentences I'd appreciate that a lot as a fall-back, regardless.
ETA: Messing with this now in the toolset, which is telling me it cannot compile the spell script because prc_inc_spells and inc_newspellbook include one-another circularly. If this is true and intentional, how do I get around this?
Could I get away with editing inc_newspellbook to not include prc_inc_spells for the duration of recompiling all spell scripts only, since prc_inc_spells is already included somewhere down the line?
ETA2: That isn't working; prc includes seem to circle-include each other all over the place. I have to assume that this isn't actually a problem for anything but the toolset script editor, then. Going to look for a way to turn this warning off, or possibly an alternate means of compiling scripts.
ETA3: Trying PRC Neverwinter Script Compiles x2.0 - this must be what you guys use. Weird interfaceless executable, documentation missing... trying the instructions from the Comments.