Loved this! My interpretation of Mise en Abyme was to create miniatures (and the opposites) of a main melody. Maybe a stupid interpretation but it made for a happy process and music I actually can enjoy.
I created a simple 8-bar melody with a marimba in Live. I then made copies that I rewarped to different lengths using the repitch mode. Making the melody half as long = one octave higher. This meant that in the end I had 8 different tracks. The lowest (three octaves below) needed 64 bars to complete its melody, whereas the highest (four octaves above the main melody) only needed half a bar.
I then made an arrangement where different octaves were introduced gradually. And then slowly removed. I added some echo to the lower octaves and reverb to the higher ones.
At 4.48 all octaves make a fresh start playing together.