It would be great if you add Sequence Download option to the download so that user don't have to wait for the the finish download the hole file user can start watching a video as soon as it start download.

free Download manager already implemented this feature.

go to settings-transfers-files
in the middle is 'sequential download options'
click on the configure button and configure away.
now go to your files tab of your transfers window and right click a file and pick the sequential one you want.