Some time back on a golf chat, we did a test. I was in the business at the time. I built two identical Harvey Penick drivers with either TT EI80 or Grafalloy Pro Lite shafts, I forget which. The clubs were identical but I laser FLOed the shafts and set one on a flat plane and one to wobble bad. The only difference was the ferrule ring colors so we knew which was which. If I recall 7 to 8 out of 10 preferred the FLOed shaft driver and several said no difference. I do not believe one person preferred the wobbler.
Personally I have my driver and fairway woods shafts (graphite) SST Pured by Golfworks. I laser FLO my hybrids/irons but as my present irons are Ping G, they were not FLOed.
Forget the ball bearing spine finders.