I'd be interested in seeing civs build more expensive ships, and be reactive to what is going on in the empire, so if Raiders are popping up, maybe they build a light escort or armed freighter, if your empire is doing a lot of terraforming perhaps building those.

Maybe some kind of Cargo / Passangers licence system (that CLS would need to buy), overall (Cargo and Passangers separately) and/or for a specific system?

or
CLS shipyards licence - how many slipways they can have and what ship size they can build?
This one is more complex to predict long therm effects.

That would give CSL some other way of spending money, therefore limit their growth.

Licence would be on overall tonage of CSL for Cargo and Passanger separately and size of a ships allowed in to a system?

Edit: system licence when set up high might result in small high speed luxury passanger ships that would have high cost to produce.

Engine technology:
I know this topic has already been raised, but every time I play I wait for the engines to reach at least the level of the Nuclear Pulse Engine.
Maybe it would be worth raising the cost of researching the initial stages of the engines, that would extend the time they can be used, both by players and AI?

Counterpoint: I use NRE tech quite a bit in my conventional-start games. I also play with limited research admin + 50% research speed, so even developing NTE tech takes some time during which I can build quite a lot of NRE-level freighters and colony ships. So personally, I prefer things as they are since I would not want to drag out the conventional starts even longer than they already are.

Not quite do because the 0.2 automines are still somewhere, possibly taking up cargo space somewhere forever! Think of the lost efficiy! 😂

...a screen that lists all events, and has a checkmark for "does this stop time? y/n" would be ideal (although probably a lot more work than I'd expect.)

Even better if the screen lets us import/export our preferred interrupts.

Like this?