Just got note from OshPark that my 2nd PCB batch is on the way: I swapped the Nokia 5110 with an SH-1106 SPI OLED display. The SH-1106 SPI was selected after a number of experiments that I conducted in order to identify the fastest monochrome display for the project. The Nokia is nice, but a little bit too laggy; it gets too blurry if refreshed fastly. The SPI SH-1106 doesn't have that issue and is crystal sharp as well as a bit faster than the Nokia: