Lilygo T-RGB Displays, LVGL & TRGBArduinospport lib - help needed

I am developing an application in C++ with LVGL, which should run on all three versions of the LilyGo T-RGB board (T-RGB – LILYGO®) as the target platform.

To simplify the UI programming under LVGL I use Squarelinestudio (SquareLine Studio 1.3.4 Documentation | SquareLine Studio). As a wrapper between Squarelinestudio (“SLS”) and the hardware I use the lib “TRGBArduinosupport” (GitHub - fablabnbg/TRGBArduinoSupport: Basic support (arduino and platformio) for T-RGB device) by Ian Hubbertz

Originally, the lib was only developed by the author for the module with the FT3267 touch chip; the modules with the CS820 and GT911 chips were not included. At the end of last year the author published an extended version for the other two boards, unfortunately without any documentation, after several attempts the lib worked for the FT3267 board, but touch functions of the CS820 board did not work, and touch and screen did not work with GT911 boards, unfortunately the author did not respond to queries.

Since I would like to use this lib for all three boards due to the significantly simplified use with SLS under LVGL, here is my question for support in debugging/adapting the lib for the other two targets. Copies of all three boards can be made available for development, and of course the whole thing should not be free of charge.