How about using Win10 Pro’s settings “Allow apps from the store only” or “Warn me before installing apps from outside the store” instead of Win10 S. Wouldn’t’ this give one the security of Win10 S plus those Win32 apps one needs?
Seems to work even for self-contained .exe files like portable apps. See How to Allow Only Apps From the Store on Windows 10 (and Whitelist Desktop Apps)