They only have to be unknown, unforeseen and/or unknowable to make the supposed "freedom" of our will irrelevent.
"Free will" or, as you want to call it, "controlled will", is not measured by accomplishment, but rather, by the freedom and ability to attempt accomplishment.
If you can grant that unknown impediments to our will are not only possible, but, likely---you have taken the first essential step in eroding the "free" part of free will.
Again you misunderstand what free will is. You are starting with a misunderstanding of the idea and then proceed to an erroneous conclusion. Free will does not in ANY way imply accomplishment.
I'm asserting that WHY we do what we do when we do it---is NOT actually known by us at all. We put a fiction on it and assure ourselves WE are doing it for cause and for reason and by CHOICE.
Part of it is, part of it isn't, part of it partially is. I don't think anyone is surprised or shocked by that. That's pretty well known (and somewhat different from your original assertion that there was no such thing as free will. A will can be free, even if we don't fully understand why we made the decision we did.)