Just for info, ''corner is always corner" is a frequent option, usually default one if 3d app supports it. Here's with - without, using OSD (Pixar Open Subdivs) in Maya LT. OSD is only supported subdiv method in latest Blender 2.8 as well, while I think they didn't enabled ''corner is always corner" in Blender 2.8, yet (UI option is present, anyway). Obviously there is ''additional story'' about these corners...