Thanks for reaching out. Adobe Character Animator provides an enhancement. The Preferences dialog box now has a Lip Sync panel for controlling how the lip-sync engine is used for detecting and generating visemes. Have you checked it out yet?
You may refer to this video:
(around timecode 5:43)
I'm still researching if there is a way to link the markers with the viseme(it is a new question for me, personally). I'll update you soon.
I'm hopeful that this video will help you with the viseme detection. Let us know if it does.