How about modifying either the wisdom or treasure hunter titles such that the better the title is, the better idea you have on wether you are going to get a gold or grape drop or not? Particularly on the free treasures in NF where you are better off waiting if you rank purple, but also in GWEN where the number of grapes seems to be higher and picks don't really drop.
I was thinking of basing how much info you know on your rank in one of the two titles. For example for the earlier ranks in the title you'd get a generic description. Advance it a little and you'll get the raw percentages of your chances.
Example
Rank1: Either a good/bad chance description
Rank2: good/fair/bad
Rank3: you get percentages that are rounded to the nearest 10%
Rank4: you get percentages rounded to the nearest 5%
Rank5: you get the raw percentage chance
A new use for the wisdom/treasure hunter title
Winterclaw