Learning diction on your own (without a school or a paid coach from the production company)
Having good diction is very important and helpful. Production companies expect to hire singers who present themselves with good diction to save production time in preparation. (They usually don't want to spend time and money teaching someone's diction from scratch, except when the production presents a show that's not in standard opera languages, English, French, German, or Italian)
For the singers who have not received diction training from school or who haven't been hired to do the production, singers usually look for diction guidance from their voice teachers or coaches. When the repertoire is beyond the diction knowledge of the teachers or coaches, singers have to seek for additional help from other linguistic experts.
If a singer can get all or most of the diction work done on his/her own, this singer could potentially save lots of money and time. It means that in his/her voice lesson or coaching, this singer doesn't have to spend time(which is money) working on the very basic things. Instead, this singer could jump into the next level of artistry during the lesson or coaching right away.
This is when Ü comes in handy. She is very good at explaining rules, helping people phonate, and catching subtle differences in singing and speaking. In most cases, Ü focuses on helping her students remember the rules, teaching her students where to search for answers on their own, and helping her students to become their own teachers.