You made a nice spider
This arduino clone looks very small, quite similar to a nano, a little bigger than a mini pro.
I hope you won't encounter the problem of intermittent bad init.
If you want to set your PID, it's still possible without a LCD or a GUI.
Not very convenient, but if you have a PC with you, it's nearly as fast as a GUI:
edit the code, and insert this after checkFirstTime():
P = 3.5; // <= your param here
I = 0.03; // <= your param here
D = -13; // <= your param here
recompile and re-upload the sketch each time you want to change the values.
This is in fact what I did to adjust several non configurable parameters during the dev.