Earlier quoted context omitted.
Why did you need to index fairly long strings in their entirety in a way that preserves collation behaviors? And why is a 768 character limit woefully bad, but a 2704 character limit is totally fine?
A URL, for instance, can't be safely stored in 768 characters, but it can be stored safely in 2704. If you then wanted to sort those URLs so that all URLs for each domain and path within that domain are adjacent, you need an index. Especially if you want to paginate over them with a cursor. Doing that without an index on the raw value is a royal pain in the ass. Hell, even just being able to sort user-submitted strin…
No, it can't. URL doesn't have any length limit, regardless of the fact that different software will impose different limits.