I think colonies were supposed to be something to start at midgame (a bit later than what I call midgame, but long before when player acquires his final killer endgame fleet), but as implemented, they feel more like a reward for winning the game because starting before endgame is very painful if player does not know exactly what he is doing. Either Alex fixes the scaling, for both named bounties and colony progression, or he adds more strategic content akin to a 4x game for the next phase of the game beyond current, which is something he does not want to add much of. I suspect next endgame would be quests or plot stuff akin to Red Planet, or invasion from overpowered boss faction.
I doubt adding even bigger thirty capital fleets for the next endgame would be good. It would just means player will avoid them, or if he has to fight them, use more cheese like Drover and Spark spam.
Endgame ten capital death fleets are bigger than anything from previous versions, including the hundred small pirate ship hordes from last release, or the 30 to 45 ships before that, or Hegemony System Defense Fleet from 0.6.2 or earlier (which was on par with a 200k or so bounty).
P.S. 0.9.1a made colonies and ships more expensive than last release (and before), in an attempt to prolong the game before endgame. Unfortunately, bounty scaling was not slowed down to compensate, which makes it easy for bounties to scale faster than player can keep up. Also, bigger endgame fleets means longer fights and ships run out of peak performance frequently, and peak performance times were calibrated during the 0.6.x days when endgame fights were much smaller, the HSDF or 200k bounty equivalent. Player without his killer endgame fleet and 500 map size will take multiple rounds to finish fights.