I'm running on the t4.0 , the code appears to be running , display is trying to work , lines across the display , I'm currently using this pinout configuration with the T4.0
// Pin connection mapping
ER_TFT0784_t3 tft = ER_TFT0784_t3(
// Teensy pin // Display pin
10, // RA8876 CS 5
14, // RA8876 RESET 11
11, // RA8876 MOSI 7
13, // RA8876 SCLK 8
12, // RA8876 MISO 6
23, // SSD2828 CS 31
22, // SSD2828 RESET 43
21, // SSD2828 SDI 34
20 // SSD2828 SCK 35
);
I am running your example .. But need to sort out why the screen is torn ..open to suggestions
I played with the SPI clock and no difference..
but getting closer ..