Once the design is there then you are not free. This we can agree upon. Couldn’t? The question is how do you do the design? Are you free in that or it is the result of some constraint so called knowledge?
The design is a free action, initiated by me, determined by me.
The hypothesis is that a free action is free. The dilemma posed in the OP assumes that there is a logical opposition between “determined” and “free”. But there is no such opposition. Free actions are ALWAYS determined.
There is an opposition between free and
externally determined. So here are your two possible arguments:
Argument #1:
(1) Either an action is determined or it is not determined.
(2) If it is determined, then it is not free.
(3) If it is not determined, then it is not free.
Therefore, it is not free.
In Argument #1, the 2nd premise is false, since an action can be determined
by the agent. (To assume otherwise is to beg the question).
Argument #2
(1) Either an action is externally determined or it is not determined.
(2) If it is externally determined, then it is not free.
(3) If it is not determined, then it is not free.
Therefore, it is not free.
In Argument #2, the 1st premise is false, since an action could be internally determined.