capuchin The Niche Gives you a nice conical for spro, if you don’t like it for filter…get a cheap flat to ad to the collection. I personally always like to have a conical in the collection. I’ve made both filter and Aeropress in the zero. It works fine.
Now if your talking about flat burrs for filter, remember they are designed for espresso, unless you get specific filter burrs and never the twain shall meet. It’s true that espresso flat burrs can do filter, but they don’t do it as well as proper filter burrs. Proper filter burrs should not be able to do espresso…if they can, by definition they are not proper filter burrs. You can taste (blind taste) the difference every time….