So, I am just updating an old post because nobody else ever posted here, but I've noticed there are several hundred views.
The firmware for 1.8.5 and 1.9.0 have been out for 3 months now, but I just updated my ER-X to 1.9.0.
I then issued the commands
configure set system offload hwnat enable set system offload ipsec enable commit save exit reboot
The first thing I did was run a test of downloading my entire data-set from my FreeNAS box, and so far I'm about 1.5 hours into the transfer on my Windows 10 Pro box, and the connection hasn't randomly dropped yet. Transfer speeds of around 1.8 MB/s.
I have no idea if this thread will help anybody else, but I found my own answer and am happy enough to post results to my old dead thread. Hopefully this transfer continues.