By coincidence I just came across this post (it’s some time back, but anyhow). I am trying to work with GPIO and the OUT CTRL setting too.: I have just posted about it here.
So I understand that OUT CTRL can only be assigned once, which makes sense to me.
But I have also difficulty finding out how and where in ACPworkbench, to make the right settings.
Can you check my post and maybe comment on the questions there?