A simple improvement. add pins (even temporarily) to the PCB. Add pin holes to the top acrylic template. No need for the lower (outer) acrylic part. Plus the pin holes force very good alignment.
Additionally, the accuracy of the PCB fab when drilling holes is going to be better than when routing the edges of the board. Just need to ensure you pick a hole diameter that matches the fabs drill sizes. (and oversize the hole a little or the fit is going to be very tight)
