No benefit.
Tanking might get you a better draft pick, but it's not like you can guarantee your way into a top 5 pick, and the Sox have too many topflight players who, while underperforming, still aren't horrible.
And why would the Sox tank and waste another year of Bogaerts, Devers, and Benintendi? To get a better player who might not see MLB for 4 years?
If the Sox want to rebuild the farm and get some cheap MLB help (which is relly the goal here), the best way is to do it via trade, where you can get players closer to MLB. The Sox have to figure out who their best trade candidates are and whether or not anything beneficial can be acquired for them. My thoughts are Betts and Barnes right now, although I am not really sure how much other teams think of Barnes at this point...