Firework Rockets are spam used in certain situations.

Firework rockets are spam used when tap-holding after firing a single rocket to boost flight. This occurs when:

1. The player is flying through lava.
2. The player can reach blocks whilst maneuvering (tap-holding) after firing first rocket

No workarounds are known at the moment that do not involve some kind of risk (such as colliding with terrain in emergency situations).