Echo moved out of audio interface as you may know to concentrate on av stuff. I emailed support to see if they were planning on releasing win 10 drivers...The answer was no (not at this time). So I guess time to think about a new interface as I plan to move from 7 to 10 at some point. ..

I don't know specifically about Audiofire, but many devices work OK in Win 8/8.1 with Win 7 drivers and if it works in Win 8.1 it will work in Win 10. 
 
If it doesn't work in native Win 10 mode, you can install it in a Win 7 compatibility mode and that should allow it to work OK.   I have to do that with my (discontinued) Frontier Tranzport, wireless controller.  I have to install that in a Vista compatibility mode, but it works OK in Win 7, Win 8.1 and Win 10.

Ok that is cool to know. Knowing how friable FW is in windows it'll be a gamble but I'm sure someone has tried this. ..