Hi,
I think you just saved my life :-) I am having an Inatek USB3.0 enclosure that apparently uses JMS567. I got very bad results on my SB while it is working quite good with another Laptop. So it seems it is incompatibility with SB. While this is not optimal at least I hope it is not a hardware issue with Surface Book.
Now I need to find another enclosure that works with SB...
Regards,
Evgeni