Crisco is good. Butter just has that amazing smell to it when it cooks with flour, almost like you are baking cookies. Bacon or chicken fat instead? That would put anything over the top. I’ve honestly never tried Crisco to make roux. It’s a very good idea. I use it to fry chicken (nothing else is close). But I’m honestly intrigued about how it could be tied into a roux.
My grandmother would deep fry lard in Crisco and serve it for dessert. 
I have no idea how she lived to be 98
The CrisLard combination probably cemented her arteries to the point they couldn’t burst and nothing would stick to the insides either, preventing the normal buildup. Either that or she somehow busted the space-time continuum by combining those two ingredients.
Eww.