Rich says that imputation is included in union with Christ and doesn’t have to happen as a separate event from being united to Christ with all that such a union entails (including forensic representation). Yet he is understood as denying imputation by selective quotation.
And Rich has been more than willing to withdraw statements that have confused people. For example: here (PDF):
I freely admit that the sentence from my colloquium essay, “My in-Christ-ness makes imputation redundant,” is open to misunderstanding. Indeed, I gladly withdraw that statement, and let the rest of the argument stand on its own. But in context, Gaffin has no real reason that I can see for taking the expression in the way that he does.
So there is nothing to rail against. The expression has been withdrawn. “FV theology” (whatever that is) makes no such claim.
For what it is worth, here is something I’ve written on the topic of imputation.