Does Google Delay or Graduate SERP Changes?

[Semush]

You can request re-indexing of a single page via Google Search Console.  It would seem to me you could use this feature to experiment with on-page changes to see the rank change to determine which changes have the most effect.  For the sake of this thread, lets temporarily forget that the relative importance on various on-page factors has already been reverse engineered to a degree so we already have a general idea to som extent.

It would seem to me if I were Google, I would introduce either a random delay period, or, temper rank change after reindexing. What I mean by that latter point is say a reindex takes a page from position 20 to 10.  If it is 'tempered' so to speak on Day 2 after reindexing it might be at 18, day 5 it's at 16, day 7 it's at 16 until it reaches the actual "real" rank.  Both the delay and or the tempering of rank change would make it difficult more difficult to reverse engineer relative importance of on-page factors.

OR, does Google realize there are large SEO firms doing SEO over several years for many sites that can examine aggregate data to determine these factors so Google doesn't delay (aka sandbox) or temper rank changes due to manual re-indexing?

[Dezzign]

The truth is no one knows... That's why the algo is such an evolving mystery

It's also different for every niche. For example in an easy niche, you can fix a page's SEO and a couple of days later it will move up the rankings 5 spots, say from position 12 to position 7. Then in a competitive niche you can spend 100 hours doing onpage SEO and the page position might improve by 1 spot over the course of 3 weeks etc.

The best way to test different on-page factors is with single variable tests in isolation using fake keywords like the guys at SIA (Search Engine Intelligence Agency) do it. Then you pin down the most effective tweaks and bust a lot of myths as well.