If I remember correctly, There is currently no way to cause multiple bolt/thrown to be done. There was some old code that seems to mention it but I think it may be depreciated or just plain removed.
I was going for the "multiple bolts" feeling with my 1-turn buff which encourages players to stand still and fire several bolts in a row. Doesn't require new mechanics, and gets to the heart of the matter - at least somewhat.
