The simple chain worked.
I noticed one thing: with a book on the list, the menu option changed to 'Sync Now (#)', where # is the number of books ready to sync. I'm not sure if that would cause it to break with a conditional (and it worked before in 5.44, so...)
EDIT: Another quick test: I set a simple chain to open the reading list options panel when the Kobo Libra H2O connected. This works as expected.
Then I went to set it to 'View To Be Read List (#)' and... the option wasn't actually available as a Calibre action?