How about a double connected expansion device that has a numeric keypad on top, and pass-through ports on the side or back.
The pass-through ports could be a preselected set, usb-c, usb-a, ethernet, hdmi / displayport, vga, for example.
Or maybe could fit the expansion card standard, so that it could meet needs.
Bonus points if it could be made for the left or right side of the laptop.