ARC DS220/450 Distortion Levels

There is very little in the way of bench testing of these "hybrid" Class D amps. I find the ARC pedigree always appealing. These things double down their output when presented with lower speaker impedances. But I seem to remember seeing one (and only one) bench test that implied that measured distortion once you get down around 2 ohms increases dramatically up to 3% or so which I would think would be umm, not so good a thing. I would be using the amp (probably the 450) to drive Thiel 2.4s which for a wide portion of their frequency output present a load of around 2ohms, sometimes dipping below that. Thoughts?