As promised in above comment, today I ran my debug script "gpu_debug4.sh" to
obtain the diagnostic output after the crash as requested above.
This output is in attached "gpu_debug4_output.txt".
Since the trace output, the "dmesg -w" output and stdout are written to the
same file, they are roughly chronologic.

If you want to look only at the dmesg-output, use
> grep '^\[' gpu_debug4_output.txt

(gpu_debug4.sh is a slight variation of earlier gpu_debug3.sh, just writing to
a local log file.)

BTW: I ran the script multiple times, crashes occurred after 5 to 300 seconds,
the diagnostic output always looked like in attached gpu_debug4_output.txt.