I would tend to use a method similar to what spdrun suggested. Run a Linux box, ext4 file system, and Samba it. I have benchmarked Windows filesystems and they aren’t pretty. When MSFT was trying to demonstrate that they were as fast on web servers as most LAMP systems, I looked at what was behind the specs. What was happening was that the drive was being shadowed into RAM and the Windows system was web-serving off the RAM image.
Another thing to consider is what type of access control/permission schema you are considering. Windows/OSX/Linux use different mechanisms.
It turns out that a Raspberry PI can be used as a Linux based file server, as can a cheap notebook with a decent Ethernet interface (use one of the old ones that is not really being used and Linux it).
With the Nighthawk, I think there are only two levels of shared file permissions. Guest and Admin. (I have a NetGear WiFi w/ file sharing. I don’t know if this is enough for what is wanted. The sharing is also a ‘web’ type vs a mounted filesystem.
