I've been building these links from Rankd SEO database to two of my own sites since February so that I can have proof that the links work.
Here you can see the impact of the links to my sites. Stats are from Google Search Console.
1st site was made in October 2018, 2nd site was made in August 2018.
1st site:
https://i.imgur.com/djyBwDL.png
2nd site:
https://i.imgur.com/4JFUwIP.png