I don't think there's a simple way we can do that. Inno Setup seems to need to be told what architectures to install the 64 bit files on in advance. We could tell it to do so on arm64 but as far as we know x64 support on ARM is still in beta so this would mean it wouldn't work for anyone who wasn't using the Insider build. Once x64 support is out of beta we'll be able to change it so the x64 files are installed automatically.