The original interview is no longer available, but here are references.

Microsoft CEO and incontinent over-stater of facts Steve Ballmer said that “Linux is a cancer that attaches itself in an intellectual property sense to everything it touches,” during a commercial spot masquerading as a interview with the Chicago Sun-Times on June 1, 2001.

Ballmer was trying to articulate his concern, whether real or imagined, that limited recourse to the GNU GPL requires that all software be made open source.

“The way the license is written, if you use any open-source software, you have to make the rest of your software open source,” Ballmer explained to an excessively credulous, un-named Sun-Times reporter who, predictably, neglected to question this bold assertion.

https://www.theregister.com/2013/08/24/top_10_steve_ballmer_quotes_from_microsoft_history/

“Ballmer: I may have called Linux a cancer but now I love it” https://www.zdnet.com/article/ballmer-i-may-have-called-linux-a-cancer-but-now-i-love-it/

“Former Microsoft CEO Ballmer does about-face on Linux technology” https://www.reuters.com/article/us-microsoft-ballmer-linux-idUSKCN0WC2RA/

Have you ensured that your setup will pass email authentication processes?

It has been a long time since email from random hosts is accepted for forwarding or delivery. This Wikipedia may help https://en.wikipedia.org/wiki/Email_authentication

I would look for a printer that supports Web Services for Devices (WSD) or Airscan (eSCL). These protocol allows you setup a scanner without installing a driver.

Here are a couple of starting points for sane-airscan. I discovered it long after I had installed the drivers for my all-in-one.

https://wiki.archlinux.org/title/SANE#Sharing_your_scanner_over_a_network

https://manpages.ubuntu.com/manpages/jammy/man5/sane-airscan.5.html

https://github.com/alexpevzner/sane-airscan

The Tweaks application has a switch to enable maximize buttons on windows https://itsfoss.com/gnome-minimize-button/

Gnome has workspaces. I currently 3 workspaces open. I regularly have four or more open. https://help.gnome.org/users/gnome-help/stable/shell-workspaces.html.en

How much do you want to spend?

If you go for a Raspberry Pi have a look at Terrapi cases as well the obvious Argon ones.

Another option would be a Zimbaboard. It is more expensive but it has dual SATA connector (you need to buy a Y cable with the Zimbaboard) and there are 3D print designs to create a single unit, e.g. https://www.printables.com/model/224057-zimaboard-dual-hdd-stand.

I’m not sure about PoE and a NAS. Will a PoE HAT or similar provide enough power for the board and the drives?

OpenWRT support on GL.inet devices seems to be complex. The following is my understanding of the situation.

GL.inet have an OpenWRT fork on GitHub https://github.com/gl-inet/openwrt This is what is installed on GL.inet devices.

The OpenWRT developers in due course try to work out how to port mainline OpenWRT onto OpenWRT onto GL.inet devices.