The OP asks about the safety stop --yes or no. Others (like myself) mention risk factors. Still others describe separation procedures. Problem is-- unless it's like 3 foot viz (in which case you may use a buddy line), how do you get separated???
Because keeping constant eye contact with a buddy (every 5 seconds, not every 10) is not priority one. I HATE when a buddy's fins disappear into the mist. Is HE looking at ME. I lost a buddy once in the Gulf of Mexico because he didn't follow the line down keeping finning into the current on a angle (as the Capt. said to). I knew he was back on the surface, so I went down the 84 feet (5 mins. bottom time) to check out the wreck-like object, and returned. If I figured he was in trouble I wouldn't have done that.
Bottom line--keeping with the buddy is priority one--or dive solo.