Can I exceed the normal RoF of a weapon using Extra Attack?
Provided you took Multi-Strike +20%, possibly: The GM may rule no or yes depending on the mechanical limits of the weapon. If a weapon has a fixed maximum rate, which no amount of trigger-pulling can raise, the answer is no. However, some semi-automatic weapons (usually RoF 3) can probably be fired more frequently if one can manage six (or more!) trigger-pulls per second. Automatic weapons limited to semi-auto can probably do this too, depending on the mechanism. In fact, some humans do this with revolvers! Check out High-Tech for a Technique that allows one to do it without buying Extra Attack.