No, you will not need to add more dimples. Tighten (and loc-tite) all retaining screws on your gas blocks. But just the first retaining screw in counter sunk in a dimple.
BCM stripped barrels have one dimple. That dimple is to insure the securest fastening of the rear retaining screw. That first dimple is mil standard measurement. It exists in the same spot on every gas block or FSB made for the M16/M4. The reason is that the machining operation to drill the vertical hole for the gas port in the gas block, is also the same op to form the hold for the first retaining screw. (actually the same on a standard FSB) So it is a standard. After that a second retaining screw position will vary with every single gas block made. No more standard. Some gas blocks are the same because they copied others, but their is not a set position. A second dimple would require you to only pick from a sepecifc gas block/s.
You can throw a second dimple in for fun if you want, but its not needed.