I still believe that says certain drops remain unaffected by treasure hunter.

I also think they added the spell effect and counter for the sake of thieves being told their TH sucks. Now instead of hanging your head in shame when you don't get dorpz people can see that you did your part stacking it up and they leave you alone about it.

It wouldn't have much (if any) affect other than placebo even if you did know. If a dev were to come on this thread and say 'Each level increase of TH increases drop percentage by .5%' you would still log on tomorrow and try to stack it as high as possible. The same thing you would be doing prior to having this knowledge.