Reducing cryogenic transport modules capacity by a factor of ten (or some other number) would be an interesting option to slow down expansion, it always feels a little silly just how quickly you can move nearly arbitrary amounts of people to me.
If I understand well what you are asking, imho it depends on the way one builds the ships.
In my current game, I am using one single colony ship, having 3,000 (three thousands) berths capacity, to start the colonies.
Civilian lines do the rest (infrastructures and people), with the only attention, from my side, to supply low gravity infrastructures where needed.
Even more, the controls for the colonists flow in the Civilian tab help a lot to avoid large and fast build up of population.
After 96 years, I have about 5.3 billion of people in 14 worlds in 9 systems. Not so fast, imho.