use SSHFS to mount Synology NAS
Just enable the SFTP Service in Control Panel->File Services.
Then mount with sshfs username@machine:/homes/username /directory
To add to the answer from @vindolin (..I don't have enough reputation just to add a comment),
As well as enabling SFTP, you also need to enable permissions to FTP for the specified user. If that permission isn't enabled, you will continue to get the
connection reset by peer error.