In terms of traits: weren't at least one or two Pentagon worlds home to rather independent minded people? I seem to remember that at least Babylon and Arcadia had very independent minded people even after the Clans took over and that they actually never managed to get this out of them. And another point: who knows i there are still some "Non-clan" settlements on said worlds. Operation Klondike hinted that the clans never got a full measure of all survivng Ex-colonists
What you are describing is basically the origin story of the dark caste. From the very beginning there were people who didn't go along with Clan society. Didn't fit in. Didn't adopt Clan ways. We know this. Over time their numbers came to include a lot more ex-Clansmen who had been kicked out of, or had fled Kerensky's society rather than just people of the old Pentagon powers who just never assimilated.
So, you are right, but it's more than a hint. It's literally the history and particularly the origin story a slice of the dark caste. With more former Clansmen joining them and their descendants in the decades and centuries since then. The writers definitely threw some nods to this in the Operation Klondike book. It also offers a useful explanation for how the dark caste got their hands on some heavy equipment and dropships/jumpships starting from the early days of Clan society.
The RPG books already give us some rules for dark caste characters. Including traits, life path stuff, etc. It's a bit generic but it's there.
To me the interesting angle/dimension (that ties in with the topic of this thread) is developing Clan subcultures of some of these various homeworlds. And then perhaps if you are creating a dark caste character who calls or called that world home, then the potential is there to merge the Dark (Bandit) Caste character rules/traits, with the rules and traits of that specific world or sub-culture. A dark caste member who started life working in the mines of Diamondstar (Marshall) may have very different story and traits than a Dark Caste member from the back alleys of a city on Homer.
I wouldn't just limit it to those worlds like Arcadia and Babylon. Particular in the centuries since, you'd have dark caste members from literally every planet the Clans ever inhabited. Because the books make it clear the dark caste have always been there and have always gotten a slice of Clan society, the malcontents, criminals, the failures, the radical thinkers, and people who just didn't fit in.