aaronpki remember some discussion of this wrt the PHP parser. one of the tricks is if you parse only the stuff inside the fragment ID then you lose the ability to associate it with other microformats on the page like an author h-card
jackybut like if I gave a parser the URL "https://jacky.wtf/likes/2020/March#20200301_303", I'd want it to only parse the MF2 found at the element under that bit
[tantek]I can't remember the issue number, but I vaguely remember the conclusions that yes we should include 'id' in the parsed result, and that extracting a specific element by 'id' was better handled in Parser APIs, that is, APIs that call parsers or that parsers themselves expose to be called, as an option to only return that "subtree"