1. Currently the maximum single size limit is set to 0, this value means there is no size limit check during single file uploads. Of course as long as the server doesn't run out of memory for keeping big files (usually >2GB) in cache.
2. there is a limit of 250MB if more than one file is being updated AND the browser does not support the FormData type. Currently this is a check only for older versions of Firefox, all other browsers are good with drag&drop caching and memory handling.
The platform supports the upload of large files, and the current configuration has no control on size, but if there is a problem during an upload such as connection drop or out of memory issues then the upload will fail.