Comparisons of the audio between the 2003 DVD version of Alien 3: The Assembly cut and the 2011 Blu-ray version. For the 2003 version, only on-set audio was available for certain scenes. The result is muffled dialogue often obstructed by steam hissing. For the Blu-ray, actors Sigourney Weaver, Charles Dance, Charles S. Dutton, and Lance Henriksen were brought in to re-record the dialogue. A much-appreciated update for fans of this cut.

Alien‭ ‬3:‭ ‬Comparing the Assembly Cut to the Theatrical Cut | Den of Geek

All 4 original Alien movie special editions are now on HBO Max; here's how they differ from the theatrical cuts

Here’s an interesting moment deleted from Alien 3: Jude slips and falls over a puddle of alien slime and human blood (belonging to David). It was scripted, storyboarded, and filmed but never made its way to either the Theatrical or Assembly Cut versions of the film.