The Oddysey is key to understanding the end of Pantheon
u/ConsiderationEasy842 had a post on the similarities between Calypso and MIST, which I noticed as well. But I think there's an extension to the rest of the last 2 episodes. The digital world + simulations are the perfect utopia -- a place free of pain, suffering, death. Calypso offered Oddyseus this basically -- Why would Odysseus so desperately desire to leave paradise and immortality though?
We see Maddie so vehemently opposed to to uploading after Caspian's "death" and her mom's uploading. Although she clearly respects the decision of others, she refuses to let her son upload. It seems confusing when she has so personally experienced and believed in the real life of UIs. But she ends up enduring 117,649 years with a hope to be with Caspian and her son once again.
Fundamentally the end of Pantheon is not about the technology or the nature of reality, but homecoming, nostos. And that is, in itself, the most important theme of both the Oddysey and Pantheon. For Oddyseus, it's homecoming to Penelope and Telemachus. For Caspian and Maddie, that means reliving suffering for eternity if that means that they can find their way home with one another again.
"Don't fear life, don't fear pain."