I have done a 2-hour test game:
Large Map, Locked Team, Pirates Inactive
All TEC Rebel Hard AI
P1 Aggressive Dark Green
P2 Defensive Dark Blue
P3 Research Light Green
P4 Economic Light Blue
P5 Economic Red
P6 Aggressive Cyan
P7 Economic Yellow
The AIs were not as upgrade-happy as I last perceived, but note that even at 2 hour mark, some of the AIs left many ships unresearched. When I broke the AI, they quite consistently research all ships fairly early, research only Tier 1 repair and armor in the Structural Subsystem section, almost none of the fancy items in the Policy section, etc.
As I was testing the game, I saw an AI starting weapon upgrade researches even when there are 300+ supply points left.
Comments would be appreciated!
(Sorry for the large screenshots)