The real thing (to me) about the lyrics is the mystery behind them. What does it talk about? Otherwise, I totally agree. Mikael wrote them in only one night. I know he was very inspired, but you just can't write so many text and expect it to be very good.
If we think about the old girlfriend of Mike who commited suicide as he mentioned in faceculture interview, my theory of songs and what they are about is this:
Girls lies Mike ( overall lyrics have lots of lie references, in lotus, coil, hex omega, heir apparent ) and they break up. The song Coil is about this and they are talking about that.
Heir Apparent is about Mike who got anger after they broke up. Song might be about his personal struggle to keep up with the fact that their relationship is no more. That's why song is so brutal.
Lotus Eater is when Mike hears the news of her death. The song is chaotic because he is surprised, shocked. Not that sad maybe at the first time he hears it. He is completely shocked thats why the song has very strange changes and melodies and feels bizarre even.
Burden is when he truly feels sad about her death. He thinks about the times they had etc and gets sad I guess.
PH is the song that I cant give a meaning.
Hessian Peel is the song that he feels sad for her children maybe. His grief for her death continues.
Hex Omega same with above but the overall emotion is regret atm. Regret about their relationship in past and sadness.
These are all my theories though.