Is there a way to use the image filename in v17 automatically?

There's more info in the release notes than there is in the manual, neither of which say much more than nothing.

I have web pages which may contain 3 or 400 images and having their original filename is much more useful than 1.png, 2.png, 400.png etc.

Loading my pages from my v15 designed site, it allows me to select, the image, right-click, web-properties, wait five seconds for the dialog box to appear, choose the image tab and then I can manually enter the filename. Rather painful. It would probably be quicker for me to rebuild the page and import all the image files again - if only it would populate that field by default. But nope, importing an image onto the page does not use the original filename. Can't find anything in options to enable it unless I've missed something. So it seems there is no option but to manually go to the properties of every image and manually type in the same filename that it is imported from.

Surely there must be an easier way...?