Well, the thing is, since some of these Spell-Like Abilities are (At will) or (Constant), It's best to keep them in the cantrips area, but their spell Lvl will be wrong nonetheless (I'm thinking about Demon Lords in the WotR campaign who would otherwise have so many (at will) and (constant) spells all over the place). The available community bestiary modules already place the Spell-Like Abilities by grouping them visually by "(X/day) name of the spell (DC YZ)" tags so your extension would be compatible with this approach as well. Or, another solution would be to ignore all information in parenthesis to determine the spell's name and while reparsing, give the information that the GM will have to manually adjust the spell DC before casting said spells for saves if its in the wrong level category.