It's been quite a while since I last played this game, but I managed to pick up a PCB after waiting around.
Average Course Clear:
729 - 4,077,500 - ALL - Autofire (30hz via. RECO V4) - PCB
Setup
Throughout the Average Course run, I did a lot of pilediver as much as I could in the first (piledive the boats in the beginning, then mid level far right side, there's two buildings that are super close together, you can just spam pilediver; mini boss I dived two times then killed, then played the level start to finish) and second levels (trees and buildings, played the level start to finish without caring about the bonus). Third level I sped through it to get the time bonus and I tried to pilediver the buildings and tanks if possible. Last level I played it from start to finish and pilediver the metal crates and whatever buildings were around. I lost two armor at the very end because I didn't know where the enemies were placed, normally I would just speed clear and ignore the other half of the level.
Will try to do Expert Course again, but I have to remember what I even did in my old run.