Is it important for open to be a “bare” attribute (not sure of the
official name) like “<details open>” as opposed to “<details
open="open">”?
The latter form is already supported (in fact the second
“open” can be any string). Just add
#+attr_html: :open any-string-you-want
The only thing I know off the top of my head is that CSS can be quite
hairy,
so I would not be surprised if this wrapper is sometimes needed.
And indeed, support for it would be missing.
Is it something that is
likely to crop up for other elements as well, such that it would be
desirable to support it in org core?
Kaushal Modi