Tried that on the front two forward facing sections of the cake when I started on the wedding cake after the trenches, bays and engine areas were done. Drilled a hole, then tried to score the plastic with my trusty #11 so I could bend and snap out the 'window'. Ended up cutting my thumb literally to the bone and bleeding all over the top of the model. Blood, sweat and yes tears being put into this baby. So given that experience and my fears of the integrity of the framework holding up and not warping over time - I decided to try my luck at just drilling through both the plate and the base, and when that cost me dozens of microbits - I went with the method I am using now.