I finally found out how to get the Fire 8.9 emulator to work. In the AVD, you have to select "Use host GPU". For more info, see
this page. This should work for other high resolution emulators as well.
In addition to making this change, don't give up too soon. It takes a really long time to install. First you get a black screen, then one that just says "Android" on it, then after a long wait you finally get what looks like a device screen.
All this assumes you already followed the links in prior messages and have downloaded all the Fire emulator requirements.
Unfortunately, after all this effort, when I connected with Designer, the screen was far from normal. For example, colors are off and check boxes do not show up at all even though the text for them does show up.
When I tried to change the layout on the emulator, it was painfully slow. For example, moving a view to the front took so long that I assumed it wasn't working and moved on to something else. After a while up popped the view.