I’m still working on solutions. I switched to Linux and so I can’t use adobe Character Animator or Animator.
I tried a free program called Papagayo, a lip-syncing program. but it doesn’t work on my system. maybe it will work for you https://www.lostmarble.com/papagayo/.
also there is Lip Sync Animation: How to get smooth and realistic results with Pixbim Animate Photos AI | PixBim ,is interesting (not free but cheap)
i tend to conceive the thing, that is, draw it (the character)in krita as I do a sketch session.
but as for animating the lipsync for free. I think at this time the grease pencil in Blender is the best option. import your drawing from krita then just have one window open with a waveform and one with the grease pencil. here.s a good tutorial. 2D Lipsync animation in Grease Pencil - Tutorials, Tips and Tricks - Blender Artists Community.
As for krita it’s open source, maybe you can come up with something. The question always is, “do you want to spend your day coding or drawing?” As for a development solution/hack, I don’t think it should be too difficult. Even something as simple as a dot marking the peaks of waveforms would be helpful.
You just have to accept krita has limitations and much of it is developed by volunteers.
even with its limitations, krita is my favorite drawing program.