Given the dual needs, it might make sense to have different allocation schemes, one that uses the built-in GC, and which allows sharing/interop outside of WASM

Given the dual needs, it might make sense to have different allocation schemes, one that uses the built-in GC, and which allows sharing/interop outside of WASM (JS, DOM, etc), and one which is entirely manual (or home-rolled GC), which does not (or makes you set a very specific set of flags which alerts the user). Without that, I'm not sure there's a way to really handle memory allocation and deallocation sanely that prevents most memory leaks.