One option is to buy an ESP32 board with PSRAM fitted and copy the SPIFFS image to PSRAM at boot up. You will then get much faster random access to the data set just using pointers. If PSRAM is available, the TFT_eSPI library uses that memory area and technique for Sprites, so examining the Sprite.c...

Great to hear about your success. The TFT interface GPIO port allocations that must be in the range 0-31 are identified in the comments in the setup file. This restriction allows single register set/clear instructions to setup all the key signal levels. The TFT signals that do not have this restrict...

Check if the OLEDs you have need SPI or I2C connections as the library will have to be selected/configured. If I2C and you do not have data on the displays then you can use an I2C sniffer sketch to find the right I2C address. Google comes up with plenty of library options. It sounds like you have a ...

This library may be of interest:

https://github.com/Bodmer/TFT_eSPI

It supports the TFT's you mention with the ESP32 either as 8 bit parallel or SPI.

Bodmer