Since potassium and manganese are minerals, not organics that could decompose, wouldn't they go through your worms like grass through a goose, or be incorporated into the worms?
Either way, if you add your vermicompost and worms to your beds, wouldnt the minerals get there eventually anyway?
Ir are you worried that they are soluble enough to leach out of the vermicompost and get lost? Some potassium compounds are very soluble, but I forget how easily it moves out of soil. Phosphate or some other ion might immobilize it.
P.S. My spell-checker corrects "vermicompost" to "overoptimistic".
