Tier 3 UPGRADES (subject to change):

DIGITAL LEARNING: Increase the amount of XP and SXP your team earns by 2/4/6%.
SPOILS OF WAR: Chance to find twice the amount of scrap after battle than normal.
COLLATERAL DAMAGE: --
COHESION: --
CHAIN REACTION: Longer combos increase damage done.

BATTLECRY: The entire team has their damage increased by 5/10/15%.
NANO SHIELDING: Restore 5/10/15% of your total HP when blocking.
STATIC DISCHARGE: Deals damage when attacked.
RECYCLIST: Items used in battle are turned into scrap.
TREASURE HUNTER: Enemies drop more exotic types of loot more often.

PRUDENT: Inventory sold at shops are 20/40% cheaper.
BLOODLUST: Recover HP after destroying an enemy.
WHITE BLOOD: Poison now heals HP instead of draining it.
TACTICIAN: Increase all stats by 1/2/3%.
BUSTER BOOSTER: Buster attacks cost 2% of your SP, but increase the overall damage by 5%.

SECOND WIND: If an attack defeats the player, SP is drained instead of HP, therefore preventing a KO.
SUBSTITUTE: If there's not enough SP to cast a tech, HP is taken instead.
KILLER INCENTIVE: Critical strikes increase all party members ready bar.
SHOTGUNNER: Improve damage caused by ALL-ATTACKS by 25/50%.
COMRADERY: Heals are increased by 8/16/24%.

As you can tell, I still have a few slots left to add more UPGRADES. If you have any suggestions for any good ones, let me know.