I would like to modify/add a database to hole wizard that would allow for me to add dowels with a slightly smaller thru hole after the dowel hole. If possible, I would like to add this under the dowel section so it does not affect our hole callouts when detailing. Essentially what I'd like to do is create a counterbore hole with the head being the dowel size, the depth being 1.5x the dowel size, and the "screw clearance" being the smaller thru hole.
Have you tried using the Legacy Hole > Counterdrilled option?