Integrate with ESPHome

A quick suggestion: ESPHome is an exceptionally well though-out modular environment where most of the work has been done in terms of integration with many third party systems. If you would develop your I/O as an ESPHome component, you could save tons of work and concentrate on your special features supported by the hardware.

Also have a peak at OpenHASP on how LVGL is approached. It hardly relies on touch functionality, though, so may not be appropriate here.