In recent updates, rules indicate that *"Motors, extension cords, sensors, controllers, battery packs, reservoirs, solenoids, pistons and
any other electrical component or pneumatics component of the VEX Robotics Design System may NOT be altered from their original state in ANY way. "*We have already cut the screw thread of reservoirs in order to maximize the space on our robot, because we originally thought the screw thread of reservoirs is as same as other aluminium components that we can cut freely. Would our action be illegal? What’s worse, the reservoirs are not sold separately. If even the cut of screw thread would be illegal, we have no idea how to restore our materials.
Even it is a problem with cutting the part of the screw thread, you can always buy an extra reservoir.