Great breakdown of the iframe/postMessage gap — that's exactly the kind of hidden lead loss that quietly drags Smart Bidding down. One thing worth adding: better match data only pays off if the campaign structure underneath can act on it — if everything funnels into one broad ad group, a cleaner signal just optimizes toward a blended average instead of your real winners. Worth checking ad group granularity alongside this tracking fix. (Disclosure: I'm from AdeptAds, a Google Ads campaign builder — account's too new for links here, happy to share more in a reply.)