Here's a rust version i made with bitmapped fonts for both i2c and SPI https://github.com/scopenews/minimalSSD1306driver/ I was running this on my pi as a demo.
I normally work with C++ on esp32 for these little displays, and in there I use a screen buffer for partial refreshes which makes them very fast !!
That’s very cool - I definitely gotta work on adding partial refreshes. Thanks for sharing!