Ok, looks like I had some code that would get upset if random midi devices where plugged in at the same time.
For my fork ONLY try adding the following line to your desired script (around line 42 before
g = grid.connect())
local grid = include "midigrid/lib/mg_128"
This is a virtual 128 grid, you can swap between the two pages using buttons 5&6 at the top the launchpad mini.
Current known bugs:
Sometimes the wrong LED lights on the first column in particular. This is not as bad as I remember it, but it’s still happening and its very hard to figure out why.
Takt didn’t work at all last time I tried many months ago 
I feel I must say this, I can’t recommend buying a new launchpad mini mk2 for the sole purpose of pairing it with Norns unless you are prepared to code to make it work, and even then I’d hesitate. But if you already have one or find one second hand for cheap … (and by cheap I mean like $20-30US)
And please please don’t buy an original launchpad, unless it’s for parts!
p.s. if you have 2 launchpad mk2 / mini mk2 then plug them both in via a USB hub. Enjoy 