So, yes, it 'simply' does EQ and can be 'replaced' by a matching EQ which matches the EQ-corrected output from Sonarworks (using pink noise as described). I tried it some weeks ago, and as far as I remember there is no crossfeed function in there.
Sonarworks, on the contrary, is all about EQing the headphone response. They do this by applying a certain HRTF (head-related transfer function), which among other things tries to artificially replace the crossfeed from one channel into the other which takes place when a listener sits in front of a pair of loudspeakers (and which necessarily is missing with headphone listening). Those try to give a perception of headphone listening in front of the head instead of the normal perception inside the head or at its sides.
Sonarworks is not to be mixed up with crossfeed plugins like 112dB Redline Monitor etc.
