It would be fun and silly and awesome to be able to drop a lone bundle of a Firework and light it, without a cannon, like a sparkler bomb situation. Board a ship drop and light a firework or a flare. Maybe give it only like a 10% chance to light anything on fire. Be able to 'tie' it to the wheel or capstan and light it.
A crate of fireworks should be flammable though. a firework crate on the deck of a ship when it got set on fire it should go off, full chaos style.
and I know this would be asking a lot with vfx and potential stability and engineering in general. I am just saying it would be a fun extra way to play with fireworks to be able to drop a single firework and light it.
