I was thinking of something like this: 
  
There would be a check-box (maybe in the pickit tab). and wht it is checked: 
  
1,Chance orbs will not be stashed anymore 
2. If there are any ORBS OF CHANCE in the inventory and If bot encouters a white item that is part of a txt file (spine bow, glorious plate, etc), it will use a chance orb. and the result will be handled by the pickit file - if it's "rare". Or stash if it is "unique". 
  
I hope you lke this idea. Sorry for my english.