Where there are two copies of a mind, there's the possibility of more. I've spent more than a little time trying to figure out how a clan of copies should organize itself in order to let the group improve the lives of each individual member, by arranging for the incentives offered to each member to nudge them towards clan-supporting behaviours. A lot of the details seem to depend on one particular issue: how much the clan's members can trust that every other member is, in fact, another copy of their mind, and some infiltrator isn't just pretending to be. This can get particularly hairy as the copies continue to diverge over time, developing varied interests and experiences; so it behooves me to make what preparations I can in the present-day, to ensure that future copies of myself all share enough pre-planning to be able to coordinate with each other without even needing to explicitly communicate. For instance, coming up with a "time travel password system" that would let a hypothetical time-travelling version of myself prove they're me to a past version of me, and would still work even if some hostile person watched the password-exchange and tried to repeat it, allows me to consider and work through a number of problems that a copy-clan would also have to solve.
No solution is going to be perfect, but I just might be able to improve the odds of my future selves being able to enjoy at least slightly better lives... and in the meantime, it's at least as much fun as any other seemingly-pointless worldbuilding exercises.
