The T4 tuner, substitute for the T3, is in stock.
This was already last year, but the development of the software for decoding the MOT data was very complex and time consuming.
The tuner is the T4A, this one is pin to pin compatible with the T3 but it has another instruction set.
There are some applications available for a grafical tft touch screen. They have been tested with a Teensy 4.0. At this moment only the slideshows with jpg-files is working. Stations that are using png-files could not show there graphical info (like all the Dutch stations).
It is still possible to use it with an UNO, but then it is not possible to use the MOT slideshow option.