Ask HN: Has anyone adopted or seen adoption of RFC8959 secret-token?

Has anyone seen adoption of the 'secret-token:' prefix to help prevent leakage of API secrets as described by RFC8959? Do API users understand its purpose and respond positively or negatively to it?

See also https://www.rfc-editor.org/rfc/rfc8959.txt and https://news.ycombinator.com/item?id=25978185