Thanks for the feedback.
I never thought, that the reason for the (for me) occasional crashes could be connected to the way you run the program. But there is some debug output which may cause trouble.

I could add an "add all"-button to the addon, but since there are multiple reruns, I believed no one wanted to add all of them.

Perhaps a filter would be more useful (like "add all shows on friday evening by a certain author"). An "invert selection" button is another possibility.