An enterprising modder has built himself a rather impressive DIY Framework Laptop with an integrated fully hot-swappable mechanical keyboard with the coveted HHKB layout. The mod makes the repairable thin-and-light laptop significantly thicker, but that extra space also adds room for sleek integrated volume, screen brightness, and keyboard backlight dials.
Starting with a 16 instead of 13 would also free up expansion module slots (in addition to the fact that the 16 has six slots as opposed the 13’s four slots). This mod uses one of the slots to run the keyboard, dials, etc. On the other hand, the 16’s input module interface is a glorified USB 2.0 pinout that could be used for this instead, leaving all six expansion module slots free.