Use a 3.5in RPi Display with an ESP32 and TFT_eSPI?

Bodmer has an excellent TFT_eSPI library that you can install via the IDE Library Manager.

There are ready-made Setup files for RPI displays.
Or you configure a custom Setup for yourself.

Yes, you will have to swap / edit Setup between RPI and ILI9341
but this saves editing every sketch file.

David.