Heck it, make the climb up to pop 10 extreeeeemly hard without cryosleeper, might as well give that thing a use since it`s so damn useless as it is.
If they didn`t want "Migration" to be that hard of an influence on population they should give the population industry a growth point bonus that scales with colony size, making the hazard pay do literally nothing outside of negating the hazard penalties or even increasing the cost of hazard pay with population size. Yeah, tensions between major factions are constant and were so for hundreds of years before the player is instantiated in the world, but the casualties of war cannot possibly outpace the population growth of all core worlds. Unless the lore entail a huge population wiping war it`s very probable the sector will reach 10^10. The sector is an Interstellar entity, and can easily grow in the 10^10th in a few tens of cycles. Earth grows about a billion or so every 15-20 years. Earth will literally do that in this century, probably in the next 40 years, 40 years!!! My playthroughs usually last for well over 50 cycles, that`s more than enough time. It is completely reasonable to say that planets can grow to 10^10 population on their own. This is the stupidest decision I`ve ever seen from a game design perspective. But again, you can do whatever the hell you want with settings.json. I honestly might change my colony limit back soon because i'm getting bored with over a dozen million credits, and over half a million more every month. (meaning size 10 colonies only have 5 max industries with my settings) Looking at the starsector wiki on Fandom, I think the original industry limit is coincidentally the same as what I use but that 5 is instead a 4. This is what I use, but you can do whatever you want: "maxIndustries":, There is also maxIndustries which you can use to change the industry limit. The var you are looking for is maxColonySize. There's plenty of things you can edit here, including the max battle size, time acceleration from holding shift to speed up the game, min/max pirate/pather bases and how long they take to respawn, max player level, xp gain multiplier, and much, much more. Go to your Starsector folder (if you have a desktop shortcut, right click and go to file location) then starsector-core > data > config > settings.json