@mawg You should see if it's possible to run GDB on your onion -- probably you'll want the Omega2 that has the most RAM, i.e. 2+. GDB offers things like breakpoints, stack-trace, read variables, capture on fault, etc.
I finally got it working with Ubuntu 17.10 and a dynamic VM with an initial 30gB size with 8gB RAM. It was building for 4 hours before I went to bed, but had finally completed by the morning. Thanks :-)
I went on Alibaba / Aliexpress and found the factory that makes the oled display 1". tested and works, cost is only like a dollar and change.
Attaching TFT displays to the onion , there are issues with SPI from what I remember. Nexon is one way to go but that is all screen driven over serial.
There are "ways" to do video over USB... kind of like webcam over USB just in the other direction :) Good luck though. Here is a reference: