Extremely beautiful production, I love all the space you're giving. It would be really easy to put layer upon layer upon layer, but your restraint, letting the reverb "breath", and letting the individual voices shine, is excellent.
The percussive beatboxing in the beginning and the choral drop at 1:05 create a really nice contrast. The choral drop feels very "holy" and slightly otherwordly, it made me feel tingly. I would say this is a very successful experiment.