Certainly the initial ~100 Pops are going to be your own species. With Tomb World that may be even more, since more planets are available for colonizing.
As
@BlackUmbrellas has pointed out, however, my whole argument is pretty tenuous, since Survivor is not an intended trait of the Post-Apoc civic. Once that's fixed, which it sounds like it is, it'll all be moot.
I understand that in many games the first many POPs will be of your own species, but there is no certainty this will be the case. This is a common feature of pacifist playstyles (player mentality, not limited to ethics) that do not engage in migration treaties, but a rarity for conquest or migration oriented playstyles that just overrun the universe with whatever POPs they can lay their hands on.
For very conquest oriented players like yours truly it will never, ever, be the case that the first hundred POPs are my own species unless I am deliberately role-playing isolationists or genocidal xenophobes: Primitives will be conquered if available, migration treaties will be signed where possible, weak neighbours overrun, and all worlds no matter how marginal colonized. All started long before I have a hundred POPs of my own species.
Nothing in this detracts from tomb world habitability being a very, very strong civic currently. I just don't see your preferred combination as being all that much of a killer, that's all.
You spend your trait points on what I consider a very marginal benefit. I mean, if you are planning on your first hundred+ POPs being own species and jumping through hoops with civics to alleviate your self-caused inflated amenities demand, why not just run the Agrarian trait and gain the food advantages without the fuss? Or conservationist + something useful, if you are worried about consumer goods costs and that's why you wanted increased habitability? Or charismatic, for that matter, and use civics to address other issues?
The only good excuse mathematically speaking for running extreme adaptability is that it will allow you to colonize worlds you can't already, and even then it is a dubious proposition as the much cheaper adaptability is sufficient to colonize the vast majority of troublesome worlds, but given that you are using the bugged post-apocalyptic civic, even that excuse fails.
So it is a bit of a conundrum to me why you consider this particular combination so good, that's all. I just don't get it.