S3 – file extension and metadata for compressed files

I store various files in an S3 bucket which I'd like to compress. Some using Gzip and some using Brotli. For the Gzip case, I set Content-Encoding as gzip and for the Brotli case, I set it to br. The files have the corresponding suffixes, i.e. .gz for Gzip-compressed file and .br for Brotli-compressed file. The problem is that when I download the files using Amazon S3 console, both types of files are correctly decompressed, but only the Gzip-compressed files have their suffix removed. E.g. when I download file1.json.gz (which has Content-Type set to application/json and Content-Encoding set to gzip), it gets decompressed and saved as file1.json. However, when I download file2.json.br (with the Content-Type set to application/json and Content-Encoding set to br), the file gets decompressed but another .json suffix is added so the file is saved as file2.json.json. I tried to also set Content-Disposition to contain attachment; filename="file2.json" but this doesn't help. So, I have a couple of questions:

• What's the correct way how to store the compressed files in S3 to achieve a consistent handling? According to PutObject API it seems, that Content-Encoding is what specified that files has been compressed using a specific algorithm and that it needs to be decompressed when accessed by the client, so it seems that the file extension (e.g. .br) is not needed. However, some services, e.g. Athena explicitely state that they need the files to have proper extension to be treated like a compressed files.
• Is Gzip-compressed file handled differently than other types (e.g. Brotli)? And if so, why and is that browser or S3 which initiates this different handling?