Matter Control v2.0 - no "save" feature - only "save as" - projects have to be renamed after every change - "control s" does not work for "save" either. What's up with that?

I'm having the same issue. The subtract option works fine for simple shapes but not one that is complex. I'm working around the problem by creating a drawing of the complex part of the object as a jpg then uploading it to Matter Control and converting it to 3D - instead of creating the complex part in Matter Control. This seems to allow Matter Control to read it as a less complex object. When I do it that way, it correctly subtracts from the base object MOST of the time but not always. My object was moderately complex. 0_1587948100053_snowflake4.jpg