How about uploading large files as tmp files and then rename them afterwards?
Uploading large styles.css or functions.php file on a slow internet connection.
Until the upload is in progress, the website is "dead" in case of php files or extremly on incomplete css files.
Upload file as styles.css.tmp<randomnumber>
Rename file to styles.css on completion
I was using Netbeans IDE before I switched to PHPStorm.
That has this nice feature.