Assuming this is worth caching to reuse many times between edits, precompile and PrecompileTools.jl for packages, and PackageCompiler.jl are the ways to cache compiled code. A package is necessary to specify the environment and isolate the compiled code to a global scope; there’s no point in reusing cached code that fails to change with the environment or is invalid because of arbitrary code ran before or afterward in the same global scope.
Still, you should continue looking into improving the compile-time or find out if it is even feasible, I wouldn’t know.