The layout I'm most concerned with is the 65% layout used by the Tada68, which has a 1U Ctrl, Alt, and Fn in the bottom row, to the right of the spacebar, as well as a 1.75U right shift. It might be worthwhile to put a 1U Ctrl and Alt in the Nonstandard Layouts Kit for that, otherwise you need the Nonstandard Layouts Kit just for the 1.75U shift and 1U Fn, and the Planck Kit for the Ctrl and Alt.