Pass Labs declines to spec their amps into 2 Ohms. Stereophile’s measurements of Pass Labs amps into 2 Ohms have resulted in a mixed bag of results. Interestingly (well at least to me) some of these "objective" results might be deemed either positive or negative depending on one’s perspective.
Pass Labs has a somewhat unusual way of specifying their amplifiers. They are not unique in that they like others before them underrate their output into higher impedances that in turn makes their output into lower impedances appear perhaps more academically elegant. On the other hand they seem to spec their amps to reflect their "Class A" output when it appears as though these seem to be more like some Pass’s earlier "Class A/AB" labeled amps (albeit with perhaps greater 4 Ohm "Class A") in that that above a certain output they can produce more power in "Class AB" mode.
Never mind, that there exists some skepticism regarding Nelson Pass’s use of "Class A" "Class A/AB" "Class AB" labels. Depending on one’s choice of criteria, the results might be perceived differently. IMHO, they are not generally especially qualified for 2 Ohm duty.