miniDSP 2x4HD as a high quality external soundcard for audio measurement

Sure, the Focusrite Scarlett 8i6 will be fine for me if i only want to do some measurements. My idea is using the miniDSP 2x4HD as a digital crossover and volume control AND having the option to do some high quality measurements without buying some extra gear - therefore the question about the quality...
 
The thing is the focusrite (and other similar brands) are designed for in and out operation simultaneously and just work and are used for measurements by plenty of people on here. I've never seen a published use of mini DSP where you would run the standard measurement loopback of PC>analog out>DUT>Analog in>PC . Might work but really not what it's optimised for. Also tearing out the heart of your rig every time you want to measure something might just get annoying the 4th or 5th time you do it.