Is it a full binary or just an object file?
If it is a full binary, then why can’t you use spirv_artifact_compile_step.getEmittedBin() wrap the resulting lazy_path in a module and @embedFile that?
This also reminds me of this topic Generating fat binary on macOS
Are any of these in the vicinity of what you are looking for?
So far I have only embedded assets so might also be that I lack some experience with multi-target builds, in that case somebody else may have an answer.