I have never used the word "Uni" in my whole life. Nor "lift" for an elevator and like you, boots are only worn on feet. =>}

My parents were both from Ontario with ancestors going back several generations. Growing up English in Toronto, we even say "to-MAW-to" and "dyew". *g*

But with the bombardment of South of the Border "English" all my life, I have to admit I sometimes also say "to-may-to" and am unfortunately used to seeing no "u"s in my words. *sigh*