Homepage Links - Serp Effect Duration

There have been studies before that described the effect of new backlinks to pages before and how long it takes to influence the positions for example in a MOZ study.

In this study, they described that it takes a few weeks for new links to affect the rankings of the pages.

If I built links to my homepage instead and strengthen my domain rather than single pages, does anyone have experience if it also takes a few weeks until real changes in SERPs can be observed?

Yeah thats bullshit. If Google crawl the page where your link is today - you can see the SERP movement even overnight. If the link is on decent website that is crawled relatively often you can expect the movement in a week or so. However there is no guarantee when Google will actually crawl the page so usually 3-4 weeks is the time period in which you should see result - pass that usually something is wrong with the link or your website.

For me, If the affect didn't appear after 2 weeks (No even 1 position movement) then the links are bullshit and they do nothing after 1/2/3 months.
Concerning pointing it to homepage, It's the right way for PBNs.

If you increase the overall power then your articles will start ranking, If an article is struggling with a medium/difficult keyword then you may need to point a few PBNS for it.

I believe it depends on the link and how competitive the niche is. I've boughten links to smaller, less competitive niches and seen results within days. Others claim it takes weeks or even months then go on about recent google algo updates, but that's not always true. So much BS being spread around the SEO world. Wonder why?