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To make AutoPlay Next Duration longer
< YouTube: Make AutoPlay Next More Than 3 secondsについてのフィードバック
After changing the script, you need to full reload the YouTube page. you can close the tab and then open enter the youtube url again
I tried to change 8 seconds setting, but it does not work. The script just ignores the number of seconds I set in "second_to_play_next_def". I did disable script auto update to be able to change script.