> a Go to Brainfuck compiler remains uncharted territory.

Not at all... Just compile your Go code to WebAssembly [1], then to C [2], and finally to BF [3].

[1] https://binx.io/2022/04/22/golang-webassembly/

[2] https://webassembly.github.io/wabt/doc/wasm2c.1.html

[3] https://esolangs.org/wiki/C2BF