Go on. Which OLED displays? Please justify your remark.
Which Arduino board do you use and which modules do you have (can you give a link to where you bought them ?).
The Uno has only got 2048 bytes of SRAM. You have to be careful.
What does the compiler say about memory usage for Flash and SRAM (dynamic memory) ?
Adafruit_SSD1306 library will take an extra 1024 bytes of SRAM at runtime.
David.