I've been messing around with this for a while and I can't seem to find the connection between fcurves and the specific shape key values they control.
I can use something like the following:
But how do I get the shape key list that "sitFix" is in?
i.e. 'Key' in this instance
Searching by name doesn't look like it will work, as Blender allows different shape key blocks to use the same name within different shape key lists, so there's a 'sitFix' in both 'Key' and 'Key.001'
Ultimately, I'm trying to see which mesh is being affected by a particular fcurve, but here I've hit a break in the chain connecting them.