@Andres I'd like to suggest the idea of running Tails from a USB stick on any x86 computer (be it Windows or Linux), or of running your Windows software on a beefy x86 computer, contained in a somewhat rough OS, Qubes OS.
For rich enough people, it might even work by enclosing an x86 ODroid-H4 Plus/Ultra in an MNT Reform. Outdated SBCs could be repurposed or given away as standalone servers.