Yeah not only is there a 28 day lag time, but _new_ content on your site is grouped with "similar" URLs, using some secret Google special sauce to determine other pages on your site to use as a baseline. This has been one of the most frustrating parts.

Or to take it further, it's still nearly impossible to use google's tools and determine that a particular DIV or Ad is causing damaging shift _in aggregate_.

Worse, it's impossible (and probably will always be) to tell the dollar value of getting all the web vitals to "green". They are pretty agressive targets for most publishers I think, but it's unclear exactly how much these fixes are worth (in additional traffic, seo performance, carousel inclusion, etc).

This is a bit "the nature of the beast" when dealing with Google rankings, their most valuable corporate secret, but still, this is a big, hard, expensive job, with relatively clear inputs and measurement, but with totally opaque outputs / ROI.