The 35/f2 ZM Biogon is a great lens but not particularly very good on the A7R and I sold mine after just taking a few test shots (Colour shift edges and smearing etc)...I then went with the CV35/1.2 ii instead.
If this 35mm Loxia f2 Biogon optically turns out to be just another reincarnation of the ZM I personally wouldn't touch it period, even with the benefit of linked exif data...I personally don't want to run every image through with a corrective profile.
I suspect that this is a newly designed Biogon that has the optical train set back further from the sensor as it's only a short focal length lens and easier to correct.
I don't particularly like the reverse direction (to what I'm used to) aperture ring that close to the camera body either but then that's me.
Re: The Loxia 50mm f2 Planar which I also had in a ZM mount was an excellent lens and very close in IQ optically to the 55/1.8 FE (FE 55/1.8 is still a keeper for now...I want faster not slower and shorter focal length).
Again I don't like the reverse aperture ring direction that close to the body but the exif data linkage would be welcome.