Wow hats off! Going to test right now!
The untz just sends note on /off messages and receives the same.
The untz 8*8 note map is from top row to bottom row as on your local apcgrid script:
midi_notes
32,33,34,35,36,37,38,39
40,41,42,43,44,45,46,47
48,49,50,51,52,53,54,55
56,57,58,59,60,61,62,63
64,65,66,67,68,69,70,71
72,73,74,75,76,77,78,79
80,81,82,83,84,85,86,87
88,89,90,91,92,93,94,95
And the untz 16*8:
0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47
48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63
64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79
80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95
96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111
112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127
Testing now 
Thanks a lot!
update:
Ok so i have been testing this with my launchpad mini and the awake script.
*I have changed the midigrid.lua file to point to the launchpad_config.lua by 
âlocal config = include(âmidigrid/config/apcmini_configâ)
local config = include(âmidigrid/config/launchpad_configâ)
I then went to the awake script and modified:
local grid = include(âmidigrid/lib/midigridâ)
g = grid.connect()
âlocal g = grid.connect()
when i sent from maiden to the norns, i get this in matron as it seems to load ok:
matron_log
hs = include(âlib/halfsecondâ)
local MusicUtil = require âmusicutilâ
local options = {}
options.OUTPUT = {âaudioâ, âmidiâ, âaudio + midiâ}
options.STEP_LENGTH_NAMES = {â1 barâ, â1/2â, â1/3â, â1/4â, â1/6â, â1/8â, â1/12â, â1/16â, â1/24â, â1/32â, â1/48â, â1/64â}
options.STEP_LENGTH_DIVIDERS = {1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64}
local grid = include(âmidigrid/lib/midigridâ)
g = grid.connect()
âlocal g = grid.connect()
local alt = false
mode = 1
mode_names = {âSTEPâ,âLOOPâ,âSOUNDâ,âOPTIONâ}
one = {
All
+1 of 2.*Aa\bS
matron
sc
norns.script.load(âcode/awake/awake.luaâ)
script load: /home/we/dust/code/awake/awake.lua
cleanup
script clear
including /home/we/dust/code/awake/lib/halfsecond.lua
including /home/we/dust/code/midigrid/lib/midigrid.lua
including /home/we/dust/code/midigrid/config/launchpad_config.lua
pset >> write: /home/we/dust/data/system.pset
script run
loading engine: PolyPerc
*i have checked the system-midi devices-launchpad settings on the launchpad and its selected ok.
*NowâŚif i go to awake-settings-output-midi, some of the launchpad lights work.
Im trying with your old step.lua but not getting any results.
I have restarted the norns, but unfortunately i cant get it working for now 
ok last edit!**
I finally got it working.
I had to change in the launchpad_config.lua file line 56:
device_name=âlaunchpad mini 2â
Before it was saying just launchpad mini, so i guess this name needs to match the midi name of the devices that norns shows connected!
Many thanks 