The inset operator uses 0.01 as default for the inset. When the face is very small than this default is very confusing (see T60226). The simplest fix seems to be to just use 0 as default. This is similar to the extrude operator which uses 0 as default as well. Reviewers: brecht, campbellbarton Differential Revision: https://developer.blender.org/D4273