Deck picture framing question - ripping boards

chrisv2

When doing a picture frame on the perimeter of a deck, if the dimensions of the deck are such that an exact multiple of parallel boards will not fill the space within the picture frame, is it SOP to rip the first and last board so everything fits correctly and balanced, within the picture frame?

If yes, then what do you do if you are using a hidden fastener (slotted) board system? Just put pocket screws in from underneath? Or route the edge of the ripped board, creating your own slot for the fasteners?

Thanks...