What an exiting day! Totally unexpected my JLCPCB order arrived & i couldn't wait to put everything together.. but see yourself:
Needless to say, it's looking very promising so far

except for the long cable being a little bit too long xD...
The NPC is working and doing it's thing incl. I2C communication. I only had to rewire the usb connector, cause somehow my kicad pinout seems to be wrong >.< ... I2C on the WiiHUD Amp is also working fine.
The connection to the bottom PCB [not in picture] is also working... only had to turn around the FPC connector.. haha.. guess i swapped the pins while turning the connector on the main pcb, even tho i should have kept them as they where.. or something like that..
besides these little issues, I'm so happy how good the pcbs fit & work. it's really amazing seeing your own designs come to life... sadly my buttons are still out of stock :/
Last but not least, a moment of silence for our fallen warriors...
[The SAMD chip is currently out of stock & I ordered the wrong version of the GC+ chip xD]