I don't know about your specific NAS box, but a few years ago, when i was researching this, I found out that most (if not all) NAS boxes run some form of Linux internally. EA support depends on exactly how the Linux has been set up, but most (if not all) only support 4K of EA data, while OS/2 supports 64K of EA data. As you can probably imagine, that can be a bit of a problem, sometimes.
My final solution was to use an old computer (P4 with 1 GB of memory), add a SATA controller, a 2 TB drive, and a gigabit network adapter. Then install eCS (now ArcaOS), and configure the services that I needed, which include PMVNC server (for remote control), Peter Moylan's weasel mail server (including IMAP), Peter Moylan's FTP server, Peter Moylan's Major Major. Web/2, SAMBA server, RSync (server mode), and a few other things. Of course, it supports 64K EAs, and it works with OS/2, windows, and Linux (specifically Mint). It just sits under the stairs, and does it's job. I usually update it about once per month, so I don't really know how long it would run, if I let it.
FWIW, windows 7, and up, seems to support EAs, but I am not sure how big they can be. I am pretty sure that they are less than 64K, and, AFAICT windows never uses EAs. I also don't know much about NETDRIVE. That always seemed to be an unnecessary option. Since the 2 TB disk contains my most recent backups, I could also use the OS/2 based NAS box as my main computer, with minor tweaking, if I ever lost my main computer, for some reason.
The 2 TB drive was the most expensive part of the whole thing (other than ArcaOS), and it has worked better than I had hoped. You do want to make sure that you have a good machine (no bulging capacitors), for reliability. Another advantage is that you have full control over what it runs internally.
