I decided to use pocket hole screws to assemble an exterior door frame that is 7" wide made of black walnut. This frame is the piece that will attach to the building, installed in the typical way using shims. (If not already clear to the readers, the door will be hung by hinges to the frame.)

Having no experience with pocket screws, I am thinking about reinforcing them with 2 dowels that will be inserted from the outside of the frame into the header and footer pieces. These would provide long grain glue surfaces. Anybody used this method and would you think it is overkill? Thanks for any feedback.