https://drafts.csswg.org/css-text-4/#ideographs

The current definition of ideographs includes two Chinese punctuation marks, U+16FE2 and U+16FE3 (see the UnicodeSet), but no other punctuation marks. These characters are not used in modern Chinese, but they are used by scholars for the textual processing, electronic interchange, and publication of ancient Chinese texts.

As an example, if the end of a section/clause/sentence is Western text, then the spacing between the Western text and the U+16FE2 punctuation will become larger per text-autospace, which is not the result users want to see.

There should be some examples of classical Chinese mixed with Western texts in the early days of Republic China, but it will take some time to find specific examples.