Well, the system is at least a bit self-monitoring; since the world only goes up to 6th level casters, nobody can make items that have higher reqs. Occasionally I'll put in a better item as a plot focus.
For example, if Kord (for whom I would use stats of a Titan) made a sword, it could be better, because as a Titan Kord can cast higher-level spells than a mortal can.
But the magic item haul of CR 1-6 NPCs is fairly light, even if CR 7+ monsters are around they're not loaded with magic items like NPCs would be. CR 10's random treasure has 1% chance of a Medium magic item, if I remember correctly.