The Autarchs did an AMA today, and Traveller came up. In particular, Alexander mentioned that he considered a Trav-like backgrounds game for character generation, but that in order to keep things compatible with the OSR-at-large, he ended up going route with character generation. This got me thinking...
In particular, I was reminded of Traveller d20's character generation, which was sort of a hybrid of d20's class/level system and Traveller's background system (technically also reminded of D&D's optional backgrounds rules, but those are unspeakably terrible, and so are omitted from here on out). Trav20 handles it by awarding XP per term, even for terms where survival rolls were failed, which I think is probably a reasonable way to go about this. But their XP numbers are... interesting, to say the least. The first design goal then: sensible and internally consistent with XP awards in ACKS.
Another thing that bothered me when rolling up Trav20 characters was that assignments per term were extremely random, and both risk and reward followed from a single random roll per term. Instead, I think it would be desirable to have a clear risk/reward decision point per term. Meaningful choices are good.
Finally, we'd probably want to be able to use this subsystem to bring characters into an existing party more-or-less seamlessly. This means at the very least henchmen and magic items should be accounted for, and possibly domains as well (domains being an interesting case; on the one hand, a domain-level character is one in most need of some background detail, while on the other, if you're joining a domain level party, perhaps it's because you don't have one of your own). Repurposing commission and promotion-like mechanics seems promising for hench-management; not sure about domains.
One possible point of annoyance is age and time; in our experience, it takes characters about a year to go from 3rd to 7th, including a fairly high number of casualties as a result of lack of cleric. I'm not sure time and aging are really a meaningful limiting factor here like they are in Traveller, even for humans (never mind elves or dwarves). So if time and discrete Trav-like terms aren't as much a thing, we're really looking for a broad-view adventure simulator; pick a danger level (perhaps using the Dungeon Level chart as a guideline), roll to survive and apply mortal wounds as appropriate, roll event, roll treasure / determine XP, determine time taken, repeat.
So those are initial thoughts. Will develop further later (perhaps after final projects are due...).