SC SUM is a Mod based on StarCraft Broodwar 1.16.1 that preserves the classic StarCraft gameplay with all its original units, upgrades and abilities but enhances the tech tree by three new unique super units, corresponding new research facilities and lots of new upgrades and abilities. In detail: 3 new super units, 1 new support unit, 3 new buildings, 15 new abilities and 3 new upgrades.
With version 1.42 two upgrades of the Siege Destroyer will be entirely removed from SC SUM. EMR Shielding lowered the energy consumption for cloak. This upgrades somehow do not feel to match the Broodwar style and game mechanics. SIF Booster raised the armor while in Siege Mode. This upgrade was to close to the concept of the Chitinous Shell of the Eradicator.
These two upgrades will be replaced by one new upgrade and one new active skill. From now on it will necessary to upgrade Siege Tech for the Siege Destroyer separately from the Siege Tank Siege Tech. Properly speaking this has to be considered as a nerf. The Siege Destroyer loses an upgrade and has to research another one he priorly got for free. Anyway the Siege Tech is one of the core features of the Siege Destroyer, so this change seems just fair.
As a replacement for the other upgrade the new Skill Long Range Scan will be available in Siege Mode. This skill allows the Siege Destroyer to increase its sight range for 20 seconds. A lot of use cases are imaginable: Obtaining an overview of enemy troops or an enemy base before an attack (as you can see in the video), scanning for incomming Scourges, increase sight range to allow earlier attack of own Siege Tanks, etc.