Umclanked is a term used to describe the act of clanking something with an umlaut mark. It's often used in a playful or exaggerated way to emphasize the pronunciation of the word.
Unclanked is the opposite of umclanked. It refers to the act of clanking something without an umlaut mark. It's typically used to highlight the difference between the two sounds.
While both words have their uses, umclanked is generally considered better due to its more appealing pronunciation and cultural relevance.