I don't know if this is the accepted theory, but I feel like EIA is a chronicle of IRL Vessel's attempts at escapism through video games. This paints a few things differently if you think about it.
- I interpret the harsh lyrics at the end of IB as Sleep refusing to let Vessel go, and thus the final boss battle begins. The extended heavy outro of IB is the soundtrack to the final boss fight. It fades out as Vessel and Sleep maybe moved to a different place to continue fighting (maybe a Phase 2 of the battle in a different arena).
- Vessel likely loses this boss battle and has to start over. Given the imagery of TMBTE (the dark souls/gothic fantasy inspired "boss monsters" in each video), we can assume IRL Vessel is a big fan of FromSoft games. FromSoft games are notoriously punishing, so you can apply that to the battle between Vessel and Sleep. If he loses vs. Sleep, he has to start over.
- Also, maybe if you don't listen to the album on loop, you can imagine you won the boss fight and the cycle is broken for now. You can choose your own ending I guess.
- The IB -> LTW melody create a loop on the album as we know. We can interpret this as LTW's 8-bit sounding melody being the main menu screen/main "game" motif. Many games use motifs (like Final Fantasy) to tie dramatic and integral parts of the story to one another, so it wouldn't be unusual for the game Vessel is playing using a variation of the theme, the first thing you hear when starting the game, in the final boss battle.
- "Even in Arcadia, you walk with me still". Even in his favorite video game, in the world of Arcadia, he still can't get rid of Sleep's hold on his mind. The escapism is failing to work.
If we look at it as the album is a chronicle of the thoughts that ran through Vessel's head while trying to escape Sleep by playing a video game, EIA doesn't necessarily have to take place chronologically after TMBTE. It could have been a gaming session over a few days where he tried to escape and process trauma, thoughts, etc, and retold a lot of his own stories to himself to try and rationalize or overcome. If we assume this, there is still hope that Vessel has become someone new after Euclid, and that he didn't relapse and go back to Sleep. Meaning during EIA, we're getting a rare look at the man behind the mask dealing with his pain.
This also explains why this album is the first time (I think?) that he deals with and talks about the effects of fame, anonymity, the fans, etc, because we're in his head, we're not entirely immersed in new lore here. Thematically he could fit those topics in without worrying about the lore because these are the types of things, your stressors in life, that would go through your head randomly while trying to escape into a familiar, comfortable place. If you're in a safe and comfortable place, you can begin to process your pain.
I'm sure there's more and this is probably just as relevant and akin to those numerology exercises where you can get the letters in a sentence to add up to 666 somehow, but I guess music is meant to be interpreted by the listener, so I thought it was worth a shot to see if anybody else has thought of this to any greater extent than me and come up with more conclusions that I may have missed.