It would be necessary to make accessible to the expressions the properties which do not have a stopwatch.

for example:
the Fill & Stroke text layers property.
What is inconsistent in the interface is that these properties have the icon Property pick whip ! But it doesn't work.
But on the other hand we can use it in the Essential Graphics panel.

Another thing about the Fill & Stroke property:
It's a property that has been forgotten in all the list of properties that we can now access by expressions to manage text styles.