expression button on ParameterRef property of ParaSeries doesn't do what a normie expects

[DeepSOIC]

When you want to type Parameter Ref, it opens a popup you can populate with an expression. When you close it, the entered expression is not written in the python variable. If you type it directly, it works.

This is because the property is just a string which is supposed to hold expression-like content, and f(x) button sets an expression to compute that string, not the actual string.

I'm not sure what to do about it. There might be a legit use for that weird f(x) button, but mostly it just confuses everyone.