Here are two more vanishing 12-plets similar to yours:
$$ \substack{ \displaystyle{◻◻◼◻◻◻} \cr \displaystyle{◻◻◻◼◻◻} \cr \displaystyle{◻◻◼◼◼◼} \cr \displaystyle{◼◼◼◼◻◻} \cr \displaystyle{◻◻◼◻◻◻} \cr \displaystyle{◻◻◻◼◻◻} } \quad \substack{ \displaystyle{◻◻◼◻◻◻} \cr \displaystyle{◻◻◻◼◻◻} \cr \displaystyle{◻◻◼◼◼◼} \cr \displaystyle{◼◼◼◼◻◻} \cr \displaystyle{◻◻◼◻◻◻} \cr \displaystyle{◻◻◼◻◻◻} } $$
I found these using JavaLifeSearch, combined with manual filtering of the search results to skip any non-polyplet patterns. Unfortunately, since the tools I used aren't really designed for this specific task, I cannot absolutely guarantee that there aren't any other 5–12 cell vanishing polyplets that I've somehow missed.