Use a footnote, but add entries for any/some to the table and use the description to say they are not implemented and to use bool_and/bool_or instead, then anchor the footnote at these entries.
Honestly, I'd like to remove all footnotes. The watermark identifying them is so small that many people don't even see that it's a link, and the fact that it's at the bottom of the page makes it even more isolated from the text it refers to.
This seems solvable in the xslt/CSS. Instead of traditional superscript print the link at normal-ish size with normal underline indicator for it being a link. On the website we could possibly even code in a tooltip on hover to show the note content without clicking or scrolling the page. And in this case choosing not to follow the footnote only means one loses out on understanding why we didn't implement any/some aggregates, not that main info, which is repeated for each, that they are not implemented. I'd call that a top-tier example of when to use a footnote. And agree we can do better styling it.
