We were similarly almost bit in the @ass a few times during the lockdowns when no one was around to stop the Windows boxes from doing what they wanted, or were centrally commanded, to do.
I don't recall if we found a workaround, or were able to get someone in the office to do the reboots.
Before I was a software engineer, I did freelance consulting and a lot of Windows system administration.
Your statement about getting bit by Windows policies only spurs more questions on. What on earth is going on that you need someone physically present "to do the reboots", and why don't you have any remote administration tooling, and why are you using Windows client OS boxes, and...
Should I send you my card, or use my (still active, I think) partner status to sell you some server or LTSC licenses? Put you in touch with a managed service provider?
It seems to me no different than writing that you installed say, Ubuntu Desktop or MacOS in the office, set up your company's webapp or some critical software to start after user login, neglected to set up any remote administration software, and then when it reboots to install security updates it's the software's fault? There were a lot of ways things went wrong before the reboot.
I don't recall if we found a workaround, or were able to get someone in the office to do the reboots.