The other page defines itself as a Stock Phrase. I don't know how exactly they are used, though.
Well, there's absolutely zero consensus on the ideas put on the table here so far. so I guess that's what keeping this one.
There is no evidence of misuse as the description won't really help you narrow down the proper usage.
I'm in favor of rewriting Yin-Yang Clash using the most common usage (whatever it is, i.e. either page examples or wicks), this is just like the case of Deadpan Snarker, which has long since evolved into The Snarker. UFMIO is a trope on its own, but should not be about people explicitly referring to it as such. It should be about the UFMIO situation itself.
Is dast der Zerstorer? Odar die Schopfer?![]()
Seems workable. Current usage in the wicks seems to be: two paradoxical forces clashes/battle with one another.
As for UFMIO, that page seem to be a Stock Phrase used to lampshade/refer to this trope, which I don't believe is a valid trope on its own and should just be merged into Yin-Yang Clash.

Maybe it's a good idea to make a separate repair for Unstoppable Force Meets Immovable Object. As for this one, I always saw it used for contrasting cosmic forces.
"For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled." - Richard Feynman