If you don't know what DKIM ADSP records are, you might want to look it up rather then looking confused.
Oh, I have a fair idea what they are, thanks. What I am not so clear on is how wide adoption is, whether the effort would be justified, whether
anything based on self-certified keys is ultimately worth the electrons it is signed with ...
Since you draw a comparison with SPF, however, I can't help noting that an ADSP seems to be merely a statement of signing policy by the sending domain. Is it actually possible to do meaningful validation of an ADSP record itself, in the absence of a particular DKIM-signed email ?