With the help of lch I made a fairly major change to DMG/combineMods.py which gives some extra room for modding spells by overwriting unused national spells. Previously there were ~136 spell slots but by overwriting unused national spells EA mods can have ~252, MA ~225, and LA ~168. By removing all the default nations and playing with just mod nations you can now have ~353 spells. This hasn't been tested all that much but appears to work. More details
here.