What if you are in a session with another timeline's you, somebody prototypes your dreamselves together in their sprite, then through time shenanigans they both die on their quest beds at the EXACT same time, however hard that may be to acheive.

Alpha Timeline, the Alpha would ascend, the other wouldn’t. In fact I’d dare say such a scenario may be impossible, it’s likely given one would be a Doomed Timeline, to avoid such a mess, the Doomed Timeline would just. Not allow the death to happen on the Quest Bed through Shenanigans.