Category of Monads on $PreOrd$

Question

In a recent paper by Adamek ("Finitary Monads on the Category of Posets", see it on Arxiv) the author introduces the category of finitary monads on $Pos$ and analyzes it in great detail. More in general, if we take preorders (i.e. the category $PreOrd$) instead of posets, we can consider the category of monads on it. If I don't go wrong, its Hom-sets are actually small sets, so we do not need to limit to finitary monads. Well, my question is if such a category has been already studied or if its investigation is still pending as an open problem. If it has been already studied, can you provide me some references on such a topic?