excellent, thank you, just the sort of response i was looking for! Doing that on the 6i6 was a hard crash the moment a second application was started. Once the 2i4 is replaced, i can hook the 6i6 back up solely for input purposes (they will not play nice hooked up together, windows struggles differentiating between 'Focusrite USB' and 'Focusrite USB' drivers).
would any kind of filter on the usb (schitt wyrd/dragonfly whatevertheirsiscalled) be likely to help? I had a similar issue with the 2i4 once (glitchy static during playback) and a change of ports (specifically giving it a usb 2.0 bus to itself) resolved the issue, and it never re-occurred with the 2i4 and 6i6 connected to the same bus despite all the other issues.