[varenc]

Homebrew is just Ruby, so there’s no way for macOS to independently know that it should present a fake x86 system to this particular Ruby script (or shell script). But when you run an x86 binary, it should just work like you describe.

[asveikau]

But wouldn't it load the right ruby interpreter? And anything installed via homebrew, it would also know how to exec?

The only problem I see is if you have a mix of different architectures wrt libraries.