I just took a quick look at SRFI 162 and have just one minor comment:

  - Ref. Draft #1 published: 2018/10/15

  - The description of char-ci-comparator is identical to that of
    char-comparator.  I'm assuming it should say something about
    Unicode case-folding using char-foldcase or some such. (I noticed
    that the implementation uses char-downcase.)

Regards, and happy SRFIng in the new year to all,

-chaw