There was a question a little while back on the English SE asking about the "plural form of i.e." (unfortunately, it got closed because the author didn't clarify what they meant).
While I was trying to answer that question, I faced the problem of not being familiar with exactly how "id est" is and has been used in Latin. I know it is the source of the abbreviation "i.e." that is commonly used in English texts today; it also seems to be equivalent in general to the English expression "that is". As I say in my answer post, my understanding is that the Latin expression, like the English one, is invariant in form, although at the time I was only able to find one example of "id est" being used between two plural noun phrases.
To increase my confidence in my answer there, I thought I'd just ask a more general question here: are there any differences in usage to be aware of between Latin "id est" and English "that is"? If there are any differences in the usage of "id est" between different periods of Latin, I would also be interested in learning about them.