Currently, it is only possible to provide download URL per platform. For most projects that and {arch} token are usually enough. However, there are tools where this doesn't work, e.g.:

Buf
Uses aarch64 for Linux platform, arm64 for Windows and macOS.

Ripgrep
Provides musl binaries for some architectures (e.g. aarch64) and gnu (glibc) binaries for others (e.g. x86_64).

It is possible to create a custom WASM plugin to handle such tools, but that - at least to me - feels like a lot of extra work for such a minor thing.