Cool! Do you have any public examples to point to? I would be curious to see how a larger project looks, given that I only use array languages for side projects, so my code is often not very legible (e.g. https://github.com/jcmorrow/advent_of_code/blob/master/day_2...).
That said, it's specifically written for an audience that is familiar with YAML detail in particular, parsing more generally, and of course APL expressions of ideas. In fact, that is a big part of what makes the code readable and maintainable: it is optimized for communicating to the expert worker not for on-boarding new developers. The latter is more appropriately handled via other means IMHO.
The poster child for this style of APL is Co-dfns[0]. It's a production APL compiler and a much larger example of the code I'm talking about. The entrypoint to read is cmp/PS.apl.
If you're interested, I'm willing to have a chat and talk more about what makes this kind of APL imminently workable, in which case there are also some personal private examples I could share as well. Feel free to reach out to the contact info on my profile here.