The reason I lean toward infused rather than imputed justification is for sanctification reasons. I can’t understand what it accomplishes if one is already fully justified. It seems like if Christ’s perfect obedience is forensically applied to you, you’re perfect. Otherwise imputation would be lacking or imperfect somehow. But then if you’re perfect, I can’t see how you could be made more perfect through sanctification. The moment you believed in Christ and had his obedient imputed to you you’d be done growing. But if his act was infused into you, then as it is being infused (continually, throughout life), you would go through the process of sanctification.
Does this make justification dependent on man? Not necessarily. One could still hold that God is the cause of all goodness in creatures (and, indeed, the cause of all positive good and being in the universe) and also that God infuses righteousness into us. God would just efficaciously and infallibly move the human will to goodness several times in a process type fashion throughout a person’s life.