I've just published draft #2 of SRFI 180.  It was submitted by Amirouche Boubekki, author of the SRFI.

https://srfi.schemers.org/srfi-180/

Here is the commit summary:

• json-write: more number checks.
• json-read: reverse alist.
• rework json-read: use a generator and implement it in terms of json-fold
• Rename json.sld to 180.sld, shake things around to make it work.
• move chibi specific code to 180/helpers.sld
• bitwise operations: cond-expand srfi 60 or srfi 151
• cosmit
• spec: link to the latest JSON RFC, RFC8259.
• spec: try to improve specification of json-generator-read and add json-fold!
• cosmit
• spec: small fixes.
• Fix typos.  Refine English.
• spec: json-generator-read takes only TOKENS as argument.
• spec: json-generator-read: avoid repetition.
• spec and code: json-nesting-depth-limit, json-generator-read, json-read fixes, and json-fold rework.
• spec: json-generator-read will yield object keys as strings.
• spec: make json-nesting-depth-limit default value +inf.0
• spec: json-generator-read can generate as obj only 'null as symbol.
• spec: json-generator-read: object key must be a string.
• check: reverse the order of tests
• spec and code: rework json-write to use the new json-accumulator-write
• Fix typos.
• Publish second draft.

Here's the diff:

https://github.com/scheme-requests-for-implementation/srfi-180/compare/f46ad4d..adf8311