It could make sense to set a good
Content-Type automatically if the server sends some default while the URL/file extension indicates a known type. However, the actual file ending should be used, not some pattern somewhere in the middle.
We had the case that some browsers downloaded our SHA256 download hashes with
.xz.sha256 file/URL ending locally as
.xz.sha256.xz files. The reason appeared to be that Cloudflare sets the
Content-Type header to
application/x-xz, while the server sends
Great to have this MIME type auto-applied for actual
.xz files, but doing so for
.sha256 files, only because the actual file extension is prepended with
.xz is IMO a bug that must be fixed. Only use the actual file/URL ending, not some pattern in front of it or anywhere else in the URL!