It is very useful in writing to suspend judgement and pour out content even if you suspect it is horrible content and not up to scratch. It is just filling space and when you play it back later you can asses the material with different values. It happens many times that what was the end becomes the beginning, that what felt necessary becomes dismissed. I’m doing it now by taking left hand ostinatos that I’ve dedicated much time to in specific keys and starting over in more ridiculous keys. I should have tried this long ago. Immediate useful pay offs though I don’t know if I have the guts to do it live. Maybe that means I must.