Since the change in #177 to use @electron/windows-sign, the package now tries to dual sign the MSI with both SHA-1 and SHA-256 (which fails):
Error: Signtool exited with code 1. Stderr: SignTool Error: Multiple signature support is not implemented for this filetype.
@electron/windows-sign needs to be able to specify that only a single algorithm is required, and then this package should specify which one to use.