No UTF-8 via SSH?

I'm trying to upload files to a webserver via SSH. The server is set to unicode (LC_CTYPE="en_US.UTF-8" when I run 'locale' on the server in an SSH terminal). However when I upload files with non-ASCII characters in their names, I get weird results: The file names are not shown correctly in the SSH terminal, and when I create files/folders using the SSH terminal, the names look wrong in Directory Opus. Furthermore, if I upload files using Directory Opus and later try to sync with GoodSync, a program I know handles UTF-8 via SSH, then GoodSync throws an error related to UTF-8 and bad codebits or something, which according to my understanding supports the fact that Directory Opus have not uploaded the files using UTF-8 (in which GoodSync assumes the filenames are).

Everything is fine when I upload via FTP (in the log files, FEAT returns UTF8). Is there any way to force UTF-8 when using SSH? In the site settings (FTP address book), everything on the "Misc" tab (where the UTF-8 checkbox is) is greyed out (including the "Use defaults" checkbox).

Unfortunately, UTF8 isn't currently supported for SFTP (only FTP and FTPS).