I did a fit test last night and it work!!!
Crammed in there I have....
- An OSHChip by @Philip1
- An entire HAPP arcade button
- ES2812B on tiny breakout board
- Li charger ripped from USB battery pack
- Li battery ripped from toy helicopter
More pictures and details to come soon. Also, I guess I should submit this to IuT as it will change the world after all.