Maybe it's time that critical systems switch to Linux. The major public clouds are already primarily running Linux. Emergency services, booking, and traditional point-of-sale have no strong reason to run Windows. In the past 10 years, the technological capability differences between Windows and Linux have widened considerably, with Linux being the most advanced operating system in the world without question.
Concerns about usability between Windows and Linux in the modern day are disingenuous at best and malicious at worst. There is no UX concern when everything runs off a webapp these days.
Just use Linux. You will save money and time, and your system will be supported for many years, you won't be charged per E-Core, you won't suffer BSoDs in 2024. Red Hat is a trustworthy American company based out of Raleigh, NC, in case you have concerns of provenance.
Really there's no downside. If you were building your own company you would base your tech stack on Linux and not Windows.
Critical systems cannot go down; therefore they cannot run Windows. If they do, they are being mismanaged and run negligently. Management should have no issue finding Linux engineers, they are everywhere. I could make a killing right now as a consultant going from company to company and just swapping out Windows backends for Linux. And quite frankly I might just do that, literally starting right now.