Aside from your conundrum I'm wondering what "ah as in yacht" could even mean; to this puzzled Brit there is no "ah" sound in "yacht". I'd spell it phonetically "yot" - do others pronounce it "yaht" or am I completely misunderstanding?
I’m ESL but always pronounced it as /jɑxt/ like in dutch https://en.wiktionary.org/wiki/File:Nl-jacht.ogg
How are you pronouncing “yaht” ? I (American) would read “yaht” and “yot” exactly the same way.
"Open your mouth and say ah" "tot" "yacht" - these all have very close to the same vowel sound to me as an American, although "tot" is more of an outlier and "taught" might be closer to how I conceptualize of the sound. I'm not sure I'd ever hear the difference in practice.