Upon first listen, my thought was “jeez that’s an arse load of reverb!”
But not a very bright thought, that as this piece makes sense as the layers start to harmonize over each other and the counter melody begins.
I have downloaded all four parts of the lab series and am going to listen to them in the car, which is my best place for listening.
One question, did you detune any of the vocal, or just choose segments that harmonized naturally?

Very beautiful work on the vocals! I find it very entrancing.

I don’t fancy the drums too much though… Something more subtle and complex would sound awesome imho.

Simple, enjoyable. My kind of song!