This is pretty much the conclusion I've come to on menadione, too. Although it makes me uneasy I, too, am just not finding enough evidence that it's dangerous to cats.Personally, I think the menadione issue is overblown based on an inappropriate review of human and rat exposure studies. Human exposure to menadione as a feed ingredient is much different than cat exposure to it as a food ingredient. The method of exposure must be considered. If water had a material safety data sheet, it would probably say that it's fatal if inhaled. The degree of exposure is important too. Toxicity is not absolute but dose-dependent. Botulinum toxin can be fatal but it can also be useful against migraines and wrinkles. There isn't enough menadione in an entire bag of dry food to add up to a toxic dose for a cat.
Vitamin K3 (menadione) in Pet Food: Is It Safe? | The SkeptVet
We feed the cats a can of Fancy Feast Classic and a "perfect portions" pack of Sheba each week because they're low-carb, high-protein foods that both cats will eat. That combination (or even just canned foods without potatoes or legumes!) is getting harder to find and even if I'm not thrilled with the menadione or some of the artificial ingredients (I do avoid sulfites in FF and am not sure if they're in Sheba -- I need to check that, it's a newer one for us) I'm not feeding them very often, compared with the homemade or commercial raw foods on the menu.