Hi Paul,
Sorry about the trouble. Yes, the site is designed for IE10/IE11. It's likely that we won't be able to produce a satisfactory experience for IE8 or earlier (and still handle 20+ other browser versions) due to issues with Javascript rendering in that release (and earlier), but we will see if we can have it degrade a little more gracefully.
[And yes..we're aware that the product GUI has troubles with the modern versions..same underlying problem, different use-case]