The 1.5" outer edge refers to the minimum individual board dimension. The smallest single PCB that can be ordered with v-score is 1.5" x 1.5".
Step and repeat refers to the panelized array of pcbs. We take the single board and copy it into an array. After the boards are in a panel we create a a .5" boarder around the array. The boards in the array are edge to edge without any space between the boards.
If you have specific requirements for the array you can provide the information in a drawing similar to the image you provided. This will work fine.
The score lines will need to go all the way across the panel for a v-score job through our Full
Feature service.
If your vscore requirement does not fit into the Full Feature service we can submit your files to our Custom Quote team for review.