Getting that 2 hours guaranteed is usually done through zombing, rigging/shopping (leaving after dying once because enemy is not pushover and joining another lobby until you find noobs to farm), unsportsmanlike behaviours (spawnkilling people on maps with no AAA. Last air event, I kept killing people in bombers flying low near airfields on Ruhr using third person mouse aim gunner to strafe people who spawned in).
If you do it through genuine gameplay -
1 kill is worth 450 score. With multipliers (0.9x for prop tier, 2.3x for SB), it goes up to 931.
For 45k star events, that’s over 46 kills needed.
Looking at some of my screenshots,
75 minute game, 7276, worth 15K progress

80 minute game, 5475, worth 11K progress

63 minute game, total is 7226, worth 14k progress

93 minute game, total is 3,633, worth 7K progress

There’s a pretty big variation in how much score you earn over a period of time flying props going for pure air to air combat. This is not entirely based on your skill either but time of day (amount of people also flying you can dogfight - the bf109 screenshot has me getting ~1 kill per 15 minutes without dying except 3 times because it was a very dead time of day)
On weekdays, I prefer to fly 1 full match and leave it at that - so 90 minutes/day usually, maybe 2 hours if it drags out. Might do 2 b2b matches if one ends early in 45 minutes and then I leave early next game.
If I wanted to do events, I’d have to ignore A2A combat due to its unpredictability in prey density and skill (10 enemies who are in VC and highly competent vs 10 enemies flying solo and competent, vs 10 newbies, vs 2 fighters and 8 bombers who J out when you approach them and so on), and instead fly a bomber for consistent guaranteed score for airfields/bases.
Furthermore, to ensure consistency I would want to start new lobbies on maps ill-suited for propeller planes flooding and diluting the player numbers to reduce chances I get caught.
Furthermore, to reduce frequency of getting caught I need to J-out/intentionally crash the moment I see a fighter to discourage them from bothering me by making it clear that hunting bombers in this lobby is just a waste of time.
Boom, you have air grind event induced ruination of an otherwise fun game mode driven by the very small amount of time you have to get tons of score and the best/most consistent way to get that score is anti-gameplay.