Current/up-to-date status on integrity checking for S3 file downloads?

[nkuehnle]

This has been previously discussed in #845, #1669, and #1830 for uploads and download.

The last explicit statement I see about downloads is from 2018 stating:

@coderall @hangzws the most common solution that I have seen is to store the checksum as metadata for the object in S3. Afterwords, you can then download the object with the checksum in the metadata and make sure the downloaded contents match the checksum. @JordonPhillips stated ETag cannot be reliably used to check MD5's. Boto3 will try to check it when it can, but there are some cases that it is not possible to check it (i.e. downloading large object via ranged downloads), in which case the metadata solution that I described above should be able to help with that gap. Let us know if that helps or if you have anymore questions.

Is this still the case, i.e. where some downloads may not have integrity checking? Is there a way to tell if the integrity of the object can be confirmed or not or to tell which objects will behave in that way if I do not know the manner in which they were uploaded?