I don’t think he did in canon, but I keep thinking of creative menu conk having used his journal as a sort of diary and having left it in his chest before he left the tab.
I want to imagine sometimes in their grief granite and diorite would just stay in Conk’s room. Quietly sitting and hardly wanting to move things from their spots. Maybe Red would too.
But more specifically; them snooping slightly and finding the journal. Despite not wanting to really move his stuff around they still want to learn about their friend even if they weren’t the closest. (They never did get to fully understand him, did they? Maybe they can even if in his death.)
They’d read it and just realize the entire time he was grieving far more than they ever realized and that he’s just as scared of losing them as they were of losing him. Maybe finding scribbled notes from when they returned to the tab and his processing Andesite being gone. That his best friends last act was yearning to be with him. That the other tab was dangerous and chaotic. That he’s scared.
They wished he told them so they could’ve comforted him somehow.
Maybe in another world he’ll know how important he was to everyone. Maybe just not this world
