Warning
Building upgrades do not constitute valid prerequisites for super weapons and thus do not suffice AuxBuilding, SW.AuxBuildings or SW.NegBuildings.

BuildingType Upgrades Are Not Viable Prerequisites
Before Ares, upgrades did not appear to work as prerequisites – if you had the upgrade, you still didn’t satisfy the prerequisite. In fact, only the most recently constructed BuildingType would be checked to see if it had the upgrade. With Ares, all upgrades on all BuildingTypes are eligible to satisfy any prerequisite logic that a normal BuildingType can.

In addition, upgrades can now satisfy a super weapon’s AuxBuilding.

What Upgrades CAN Have or Do
Superweapons (this will add to the structure's superweapons, not override them)
Power output/drain
Weapon (Note: Superweapons override weapons, so structures may not have both)
AIBuildThis: In TS it works. In YR, AI has problem in building/rebuilding this if the parent building does not have positive power or being powerplants.
AIBasePlanningSide (in RA2 and beyond)

Known Upgrade Problems
Upgrades can not give the player ability to build new unit(s). If you attempt to do so, each building built after the plugin causes the new unit(s) to dissapear from the sidebar, making them unbuildable again.

The AuxBuilding superweapon logic does not work when upgrades are involved (either AuxBuilding=upgrade or the upgrade has the superweapon itself).

A building can provide a maximum of two superweapons - if a building has more than two superweapons when adding up the superweapons from the building itself with those provided from upgrades, only the first two superweapons will get considered.