That is it really. Make it so that they are created instead of regular meatballs when monster meat is the primary ingredient.
Monster meat is supposed to be what players resort to when desperate, or can be used through more obscure ways to produce healthy food. The fact that meatballs convert them into a healthy sustenance for no reason defeats this balance, and is a blatant meta you can find in any match.
Here. The community listened. The horde of berries and ice, gathered under the single banner, about to lay siege to the spider kingdom.
(Honestly though, the reason for one monster meat being fine in meatballs, to me, is that it's okay since you really don't get much meat in meatballs, so the toxicity is negligible.)