Here is how you can use the 12vTools XLR and the SPFT.250 to create trim rings off of any external shape. This opens a wide range of possibilities for fabrication such as flush mounting drivers, amplifiers, iPad's, tablets etc. You can also create your own template shapes with inserts for vinyl wrapping starting with this technique.
Here is a quick little video showing my EXP 6 bearing Spiral flush trim bit navigating stacked templates. The extended bearing wall allows you to clear gaps between stacked pieces without worry.