Doing much the same thing. Face similar issues.
A lot of the complaints about Starlark as a programming language, and the proposed alternatives, seem to me to miss out on the UX advantages of having pythonic scripting (which so many folks who have taken a random "coding" class understand intuitively) whereas, e.g., using a lisp or lua would not. Further, having a language and runtime designed for safe use is absolutely critical, and trying to embed another runtime (js/wasm) and manage to lock it down successfully, is a much larger undertaking than I think folks realize.
> Further, having a language and runtime designed for safe use is absolutely critical, and trying to embed another runtime (js/wasm) and manage to lock it down successfully, is a much larger undertaking than I think folks realize.
For what it’s worth both Deno and workerd from Cloudflare give you starting points to run JS in a very locked down sandbox.