For real though, I enjoyed a lot of it but thought the narrative wasn't as cohesive as it could have been. For me, it could've been truly great but the way the plot panned out left me feeling pretty hollow. I get what you mean about it having more depth than Hereditary, but I just found Hereditary to be a more satisfying film from a horror point of view.
I need to check out this Beyond the Black Rainbow that you speak of.
Black Rainbow is best described as a complete mindfuck. It's the debut film from Panos Cosmatos, who directed one of the best films of last year: Mandy. On first viewing, you will likely be confused/disoriented because it's slow and definitely NOT a film for everyone. It starts off as a 80s sci-fi acid trip and morphs into an 80s slasher. After watching twice and reading some in-depth analysis on it, it's just one of my favorite films of all time...it's just so badass.