My domain: ilovescratch.us.ci
Even though "us.ci" is in the publicsuffix.org/list/public_suffix_list.dat, I still encounter rate limits for "us.ci" domains: too many certificates (50) already issued for "us.ci" in the last 168h0m0s, retry after 2026-01-12 06:54:26 UTC: see Rate Limits - Let's Encrypt
Updates to the PSL take some time before they are added to Boulder. See: Trying to generate SSL with .bd domain - #5 by Osiris
I don't have anything more to add. I changed the title in hopes of drawing attention to it.
I can see the PSL was merged late Nov for us.ci but I didn't check the go package for it.