Is it not correct that not all on board sound chips support WASAPI?
I have one old W7 64 bit laptop and when I tried to do the loopback test using WASAPI it would not work. It also wouldn't use WDM mode. They would load and run the audio test, but I couldn't get sound to record. So I had to do my test on my W10 desktop.
Later I have been using WASAPI on a different W7 laptop for a few months without issue. I now switched to Asio4all and it works better. But that is a good point about Asio4all co-existing with a Focusrite driver. In the past this was a known issue, But I think ASIO4all has matured and they fix things with updates. I could test that tomorrow at work where the laptop is. I could take my 6i6 and see what happens.
Yes please don't even think about MME mode that is not an option. See below.