Hairsational Directly from the Wifi router which has a DLNA server built in. Portable SSD plugged into the Wifi router via USB, router being the limiting device here (USB 3.1 Gen 1, 5 Gbit/s). Since HS supports DLNA, this set-up has worked for me significantly better than everything I had before.
In the meantime, I have tried plugging the SSD directly into Q3 and using 4XVR player. I think that's currently the only player supporting this. Results are better than over Wifi but the horse ride still plays a little choppy.