+ - TouchCursor layer seems interesting
+ - It sets up a layer with cursor keys on the home keys
+ * The jeremy-dev keymap has some very interesting concepts
+ - Shift hands outwards; the special keys go in the center
+ - Symbol layer has some compound keys for C operators like /=, *=, -=, +=, ...
+ - This is likely what I'll use for my XD75re, and maybe I'll fork a
+ planck keymap for similar