So I did a bit of digging, and ... I nailed it.

I'm not even close to an expert in Kant, and in fact have never bothered to read any of him, after His Exellency Bishop Williamson exposed him as total garbage, but kudos again to His Excellency in giving us enough of an overview to recognize this garbage when we hear it. That's what I said in another post, that His Excellency didn't just give us fish (i.e. thoughts), but taught us how to fish (how to think, and to recognize subjectivism in all its forms). Based on what I was armed with by His Excellency, I sniffed this "concrete Church" nonsense out pretty quickly ... as phenomenological hogwash.
I vaguely recall after Bishop Williamson had discussed how the Germans (who in his estimation, while being good at other things, completely suck at philosophy), even German Cahtolics, have had this inordinate admiration for Kant, having been perhaps their most renowned "philosopher" ... and I kindof recall him taking a subtle swipe at the German Trads (perhaps even Schmidberger) for being somewhat contaminated by this thinking themselves, saying that the Germans had this need to salvage Kant by attempting to reconcile his philosophy with scholasticism / Thomism / Aristotelianism, and that it was a doomed effort that could end only in disaster because they're simply not compatible.