Nevermind, fixed it! I played around a little bit, and using the following in my Configuration.h ended up working for me:
#define ST7920_DELAY_1 DELAY_NS(400)
#define ST7920_DELAY_3 DELAY_NS(400)
#define ST7920_DELAY_2 DELAY_NS(400)
Delay 1 was not in the original file, and the default 250’s for the others weren’t working. I didn’t tune these too far, so could be further optimized.