It took awhile to download Blender 2.93 (Beta) and install. Then I got the new exporter and tried it out with a new vocal animation. Result :
The vocal animation was done quickly and the audio created as well. It uses the same head that I have previously used and Jeff has posted on his github pages.
Just a little background on the music - it goes back about 65 years to my youth. I lived in a seaside tourist town with several theatres. One theatre had a comedian who did impressions of the singer, Joseph Locke, so I got to know his songs. The music used is a little snippet of a Joseph Locke song from the 1950s. He was very popular in the UK at the time, though he did run into trouble with his taxes! And they made a film about him with the US actor, Ned Beatty, playing him.
At a first quick glance, there seem to be a couple of issues with controlling the animation length, but maybe more experimenting and getting used to the shape key exporter will sort it out.
In the meantime, a big thanks to Jeff
Stay Safe All, gryff