the last time I did social signals (some 6-7 months ago) they worked. Contrary to what you might think, or to what other SEOers will tell you social signals actually are not treated like backlinks. You can have millions of signals (especially if you get some traffic with those signals too) in a short period of time (1 week for example) and your site won't be penalized.
Again, I'm not sure if this is true today given how retarded google is and how much they are trying to shake us off their search engine, but 6 months ago I purchased 150k social signals to one of my websites and all of them got delivered within 4 days or so and nothing bad had happened to my site. It's true that the website wasn't ranking at the top anyway, but it still didn't get penalized / deindexed / deranked or whatever. Google sees social media signals as a normal advertising campaign