While Particle Illusion 3.0.4 is a legacy version (originally by Wondertouch), current versions are developed by Boris FX. If you are using the classic version, "all extras" typically refers to the extensive Emitter Libraries and Pro Emitters collections. Quick Start Guide for Particle Illusion
: Instant access to realistic fire, rising smoke, explosions, and magical glows. Motion Graphics Accents particle illusion 304 all extras
“All extras” suggests:
Combine Emitters: Don't just use one. Layer a "Smoke" emitter under an "Explosion" emitter and add a "Sparks" emitter on top to create a professional, multi-layered look. While Particle Illusion 3