Before I go to the trouble of reinventing the wheel. Try this experiment. Install Little_Dragon's "Victoria 4 Phonemes". Open the "Victoria 4 Base Phonemes.cr2" in a decent text editor, I use "EditPadLite", "WordPad" will do at a pinch. About 8 lines into the file, you will see a line that reads:

readScript :Runtime:Libraries:Character:DAZ People:Victoria 4 Base.cr2

Try changing this to read:

readScript :Runtime:Libraries:Character:DAZ People:Michael 4.cr2

Resave the file as "Michael 4 Phonemes.cr2". Then follow the instructions in Little_Dragon's "Victoria4Phonemes_Readme.txt" using "Michael 4 Phonemes.cr2" in place of "Victoria 4 Base Phonemes.cr2".

I think there is a good chance it might work. V4.2 and M4 are very similar, but I think Little_Dragon's file was made for V4, not V4.2, so it depends how much has changed in the meantime. Anyway, it's worth a try, and would save me a lot of work if it does the job.