Would be nice if the channel name could be included in the filename that is saved

Rather than put the channel name in the filename, make a directory with the channel name.
all the videos/playlists would be located there.

Put the uploader/publisher in the filename with the upload/published date.

The Channel name and the Publisher may be different i.e. Favorites playlist

Let us be able to arrange the fields in the filename as to the sequence depending upon the type of download.

Setup a Smart Mode Label with the ChannelName to define and save this information.