What if a chronically ill person plays sburb and dies of their illness shortly after entering? What's the timeframe for getting their body to their Quest Bed, if there are no "injuries" for the dreamself to take on?

I mean, death itself, not breathing, heart stopping, is in itself an ‘injury’ so to say. So that would still slowly happen. Your Dream Self also starts to get the wounds IMMEDIATELY after being placed on the Quest Bed, by the way- But I don’t think there’s a canon example of how quickly the wounds are inflicted outside of the Quest Bed, but both John and Vriska’s Dream Self got pretty messed up quickly immediately before Ascending. Roxy hesitated to smooch Jane’s bloody deceased body for a while until Jake kissed Dirk’s head and he doofed her away to do it himself, so there’s at least a couple of minutes. It seems like it may be a relatively short window of time though.