Self-Signed UWP Apps in Windows 10 S

I've got a UWP developed that runs just fine on Windows 10 for desktops and phones. Because the app isn't in the Windows Store, I've got it configured to be self-signed, and that seems to work just fine. However, we now need to support Windows 10 S.

I can install the app just fine in 10 S, but it fails to open and the event log gives me the following error:

Activation of the app {App name} for the Windows.Launch contract was blocked with error 0x80073CFC because of an issue with application binary {App name}. This could be because the binary is unsigned, contains an untrusted signature, or has been corrupted or tampered with. Reinstall the application to fix this issue.

I think this has to do with Microsoft wanting all apps installed on Win 10 S to come from the Windows store. Does anyone know of a way to get around this (other than upgrading the laptop to a full version of Windows 10)?

Sideloading of self-signed apps on Windows 10S is not supported.

To test your app for the Win10 S configuration before releasing it via Windows Store, please follow this guidance.