I may consider using HOCON [0] if I see any traction, bust after writing a lot of YAML and even making my own YAML-driven tools, I feel its shortcomings are overstated. I got bit by corner cases maybe three or four times, and they didn't take long to debug.
For the authors, I suggest a TL;DR with some basic examples. People tune out pretty quickly. You want the 10s take away to be "I like it" and "this person has really thought through it". You have achieved the second objective with what you have.
[0] https://github.com/lightbend/config/blob/main/HOCON.md