So that's round-about but going to "My Books" (which seems to be their new "library") downloading it gave me a .acsm file which can be opened with Adobe Digital

So that's round-about but going to "My Books" (which seems to be their new "library") downloading it gave me a .acsm file which can be opened with Adobe Digital Editions software which will then download the epub. So it works, but surely there's a saner way!! Also note that you can't download the book from the book's page (which only points you toward their app), but only by clicking the dropdown menu on the My Books page. Thanks for pointing me to it!