I never made games, but to share ascensions/tek grams in a single cluster for a single account, servers can probably be programmed to do the following:
1, include a saved file that have a list of gamer IDs and the ascensions/tek grams they have acquired
2, compare the said file and a character when a character is downloaded into the server. If either a downloaded character or the shows that player ID have acquired an ascension/tek gram, then both are set to have this ascension/tek gram unlocked.
What it means is that once a character enter a server, the server remembers its unlocks, and will apply it to other characters. If a player have alpha Rockwell on one character, alpha overseer on another, all alpha bosses but not ascensions on yet another character, then these characters can be moved around and all 3 of them will gain all tek grams/ascensions.
Since its impossible to move characters between pvp and pve, private and public, or single and online. An ID can not share ascensions/tek grams cross cluster: ascensions/tek grams are shared between characters only if they are capable of transferring to each other's servers.
As for imprint sharing, currently creatures recognize character ID, but they can also be configured to save a player id. Whenever transmitted or released form a cryopod, creatures can ask server "what is the current character ID of this player" and update character ID accordingly