I don't think there is actual free will, and I think the appearances of it is just how our minds present things to us -- that is, I basically agree with the description you give.

But I object to statements like:

> the free will is there but only as a convenient abstraction.

Here's an analogy to illustrate my objection. It's inaccurate to say that the person Santa Claus literally exists but only as a mental concept.

The accurate way to put it is that the Santa Claus person doesn't literally exist but we have mental concepts describing such a person.

Free will doesn't exist but we have a mental concept of such a thing.

That's the honest way to put it.