The Advanced Multi-cannon’s key feature is that Anti-Xeno ammunition can be synthesized for it on the fly, allowing the weapon to be used in combat situations against Thargoid vessels as well as human ones. Unlike dedicated Anti-Xeno weapons, the Advanced Multi-cannon does not have experimental weapon restrictions, allowing pilots to equip as many as their ships can accommodate.
Use of this weapon is only likely in Anti-Xeno builds. Available as a size 1 and 2 fixed variant only, the use of this will be situational to your Xeno Build goals. See our section on Anti-Xeno / Thargoid matters for ship builds and usage related to this weapon, and read the section on Multi-Cannons for additional info.