What details should an Ego try to take into account, when they save a copy of themselves in a time capsule set to wake millennia in the future?
The simplest, if most depressing, scenario that would need to be planned for would be for that fork to be the only sapient being left in the universe. In which case they'd have to be prepared to Von Neumann themselves up to spread across the stars; this not only requires blueprints and an initial set of hardware, but also softer bits of info, from the more structured aspects of legal systems to enough social skills to be able to cooperate with further forks.
Another scenario: If Von Neumanning is impossible, but it's not confirmed that all other sapience is extinct, then the fork could try to simply maintain its existence long enough to eventually be rescued.
After that, complications involving other entities get increasingly complicated; anyone care to make a stab at how likely any given general plans would be of use, especially compared to how much investment would be required to make that plan feasible?
As a further variation of this idea: What could somebody who lived a century before the Fall do, planning for similar scenarios? (Eg, a present-day cryonicist planning to have a few terabytes of data stored on long-term archival media along with their body.) Grabbing a copy of some jurisdiction's legal code and precedents, to use as a baseline instead of having to develop a new one from scratch, seems entirely plausible; so does studying various subjects such as programming, mediation, and astronomy; writing down an offer of a reward for revival seems less likely to bear fruit. Or maybe I'm wrong here - I'm curious what directions your thoughts take, even if you don't have any final answers. (Of course, if you /have/ answers, I'd love to see those, too. :) )
Thank you for your time,