It wouldn't help learning the pure magic style from scratch, but that's not what they're for. Gleaning some new insights seems plausible at least. If nothing else, on who the magic interacts with dhar, which seems useful when you're dealing with a miscast.Sure the Eshin have the Lore of Stealth, but learning ulgu insights from from it would be like trying to learn Shysh from books on necromancy, no treally comparable.