So I can't get the terminal to mine.
It just keeps running in a loop loading the power settings and detecting the GPU's, where as in v18 it'd load the cuss cores it just restarts the initial detection phase over and over.

There are 2 things that come to mind:
1:
You have entered an invalid COIN selection in 1bash; perhaps a typo or using lowercase letters. Try changing 1bash to :
COIN="ZEC"
to test.
2:
If that isn't the problem then;
there is something wrong with the image: I would try another USB key or re-imaging the same one.