OK. So you are saying that it doesn't follow that, if a creature is a rational agent, then the creature has free will/makes free choices? If so, cool.
I think it's a problem for Thomism to hold both that God is the first cause of every motion, first cause in any hierarchical order of causes, and to hold that acts of will are motions, and to hold that the controlling cause of the rational creature's acts of will is not God - however much Thomism wants to affirm concurrentism.
I asked my earlier question because the usual answer is that the agent produces an effect in the recipient in line with the mode of being of the recipient. And in an argument for LFW, it would beg the question to define the mode of being of the recipient, the rational creature, in a way that already includes LFW as one of its properties. But I gather you're not making such a move.