knc1 -- thanks for clarifying. Too good to be true, it seems.
Using a router could be an option.
Not quite as nice as wirelessly connecting...
I suppose if I really was going to a ton of effort I would just override the connect to folder driver in calibre, and copy-paste the Kindle code over. After all, I run from source anyway! That would be
one was to get sshfs working as well as a USB connection.
Really, usbip only has the one advantage that I can see (interfacing with software via USB vendor-ids).