a little homebrew app to allow toggling the touch screen...
using hid:sys cmd 1320 (WakeTouchScreenUp) and 1321 (PutTouchScreenToSleep)
https://switchbrew.org/wiki/HID_services
download from releases https://github.com/iamasink/touch-screen/releases
put touch-screen.nro in your sd card's switch folder :)
thank you @Boccher for idea and testing