You won’t get pure randomness, but you will get different length scenes to your specification out of a single clip.
This Clip has 3 scenes to it. 1 is a panning circle., 2 is a line, 3 is a panning dot
On circle, Add a saw wave to brightness. Set the clamp min : full, clamp max to 90. so it fades down at the end. Set the speed - 8bars. Repeat : 1, delay count 0. This is 32 beats long.
On
the line clip- triangle on brightness. See pic for settings. Delay is 30( for some reason I can’t Dial in certain delay numbers like 16,31,32). Repeat is 1 so it fades in and out once. Speed is only 4 bars this time.
On panning dot, copy triangle osc from line, - delay count 48 beats. (32beats from circle, 16 beats from line). Change the speed to 16 bars.
This clip should play through 3 scenes at predetermined, albeit varying lengths and fade to black. Just keeping copying over the triangle osc. to every subsequent scene with the clip.
This same technique on a single scene will yield a highly expansive output.
Appologies if scene isn’t the correct lingo for liberation. I’m an old lighting guy.