SSD1306 LCD and nonblocking libraries?

Just as a general observation, I assume you mean OLED when you say "SSD1306" ?
If so - as a general point, those SSD1306 OLEDs (like the 0.96" displays etc) are terrific displays but they are not very fast anyway. You might like to tinker with the code, but the display itself might be a limiting factor in terms of performance.