WASAPI has been turned off in the alpha 2.0.6 - but with WASAPI loopback retained to facilitate recording audio that is playing on the computer.
I tested WASAPI loopback extensively and now use this all the time for my production recordings of webcasts - with excellent results. So my recommendation is use it
My Tosh laptop (like many modern laptops doesn’t have a line-in) I circumvent that with the use if an external USB souncard - I record from FM radio and I digibitted all my LPs that way - see this sticky thread: Sound Card Reviews
WC