The Box account established for me at work by campus IT does not support many third party apps.  Among other things, this means that I cannot use the standard OAuth authentication for a cloud account to hook up to SME.  Work arounds are WebDav and FTP access.   Unfortunately, neither of these work perfectly.

WebDav would be a good choice, except that does not support maintaining modification time of files when connecting with with WebDav. does support mtime preservation when connecting with FTPS.  See    

All of this is background to say that SME's ftp connection does not yet provide the needed feature set to support keeping file timestamps in the same way that the native sync client would.  Other ftp clients (FileZilla, SmartFTP, lftp) support this feature.   

Is there any hope that SME's ftp feature set will be extended to allow file timestamp preservation?

At this moment we don't save modification time on upload to FTP and WebDAV provider.
It seems it is possible but may require one additional request after upload to send the modification time to the provider, So it may slow down the upload.

I will add this as a feature request to our roadmap.