Hmm…
Per the rules, there might be semantics.
Rule 3: no explosives.
Explosives, per Merriam Webster:
able to cause an explosion : used for exploding something
Explosion, per same:
the sudden, loud, and violent release of energy that happens when something (such as a bomb) breaks apart in a way that sends parts flying outward
Pyrotechnics, per same:
-a bright display of fireworks
-a very impressive show or display that requires great skill
Now, being that most (3/5, i.e. “crowd choice”, “builder choice”, and “funky fling”) of the metrics are subjective, one would assume definition 2 of “pyrotechnics” should be applied “with extreme prejudice”.
As for your question, though, can you apply “rocket power”? I say yes, as most rockets are powered by non-explosive fuels, by definition, since the causation of “parts flying outward” is most undesirable to the intention of “rocket power”.
But should your “rocket” become “explosive”, you’d have broken the rule, most certainly.