So I tried some grayscaling on the LCD, but my ESP code runs out of sync with the LCD that updates every pixel in a certain frequency that I don't know. So I get a sometimes grey, sometimes not so grey value and an analog TV style walking distortion on it.
According to this datasheet there is an OSC pin, that accepts an external clock for displaying. So here comes the "what if": could I use an attiny and spit out a frequency of around 32kHz and a "frame" / vsync pulse for the esp to check / interrupt on? that would be so cool. I could use the data in / MISO for that (tiny would be connected to CS of display as well).
Oh the stuff you think about when you have no lab / hardware :D
Cool side note, the SSD1305 that's on the 1.54 OLED has exactly that integrated. [doesn't seem to be broken out on the cable though] Also from the datasheet: "There are 4-color selections to support monochrome or area color OLED/PLED." -> I think that has something to do with those split oleds, where there's an orange bar on top of the blue display etc.
found a SSD1327 controlled OLED that's 128x64 and monochrome.