This workaround does not work on
unsigned arm64 app bundles on an Apple Silicon device. Yes, there are workarounds on the developer side such as signing with a self-signed certificate. The user who downloaded it could even sign it themselves.
But regardless of holes and backdoors in the gatekeeper system, the point is that you can't download an unsigned, native binary from the internet and run it on a modern (apple silicon) device with a user override. Not anymore. You have to sign binaries in order for users to be able to override-launch on their own systems. Gatekeeper will stop any unsigned binaries from the internet from being run, full-stop.
And yes, I'm both a user of macOS and an open-source software maintainer. One of my apps has releases built using a cross-compiler on linux, with a reproducible build configuration that was tricky to get setup and hadn't been updated to handle code signing. When M1 devices came out we had to go through the painful process of replicating a lot of the Apple codesign tooling on Linux so that we could apply signatures from within the reproducible build environment, just to enable to the user to right-click override like they used to.