Well, at least the spells that use Spellcraft (INT based) to calculate parts of the DC wont be.
I dont suppose there is any chance of adjusting those spells to use the number of Caster levels instead? Or maybe something like Caster Level + 3. This would mean that a Bigby's thrown by a level 40 wiz would have the exact same DC as one thrown by a level 40 sorc (assuming they have the same feats, etc). It also means any multiclassing will weaken the bigbies DC's. Which isn't a bad thing
I guess the downside is that it means people reading out scrolls wont have spells as powerful as people who can actually cast them for real. Which may or may not be a good idea.