As long as it works for you, any mnemonic is perfect! I’d hesitate to have everyone use yours for this word because if “minotaur” is the connection, it’s possible people will write みのた to track the English-to-Romaji path there. I know that leap is not unheard of for WK-supplied mnemonics, but I’d want to minimize it. (Edit: Though to be clear I still like yours more than what’s there now! I never looked too hard at the “me natto” because of what’s in my second paragraph).
港 is one of those vocab words where a person can benefit from exposure to Japan–the reading is something I know from place-names (but never knew what it meant, of course). So the connection to something that’s already in my brain is much stronger than stuff I’m learning for the first time. Specifically, there’s an entire ward / district of Tokyo called Minato / Minato-ku / 港区. And even closer to home for me, there’s a famous area of Yokohama called Minato Mirai, and though I’ve only ever seen it written out in Hiragana, I assume that the みなとみらい comes from 港未来, and means “Harbor of the Future” or something, given that it’s on the water and where the big glitzy buildings are.