So I remember a while ago the discussion about familiars, with the release of RoP:M... and I stumbled upon something similar in my saga recently when a Merinita character decided to bind a faerie as his familiar.
Well, Faeries do learn, that much is clear - but what they learn are pretenses and can be spotted by real specialists quite easily. So how can a Faerie familiar ever help a magus do labwork, if its Magic Theory is just pretense?
And on a similar topic, do Faerie animals get the Qualities their mundane counterparts do?
Note that pretenses are just as effective as the abilities they mimic. It's just that an expert human observer can tell that they are not "natural". So a Faerie familiar can help you in the lab. But your apprentice is likely to notice that its advice/help is effective even when it should not be.