I've been using ergodox -> dactyls -> redox -> redox manuform and decided that this layout is the sweet spot for me. I'm not familiar with openSCAD so I used solidworks and it's completely manually modeled. As for less columns or rows they don't really work for me since I'm from East Asia and need to switch between languages inputs so 70 keys is the minimum for me. For example num rows are required to type Traditional Chinese and it'll be hell for me if I have to switch between layers for numbers.