yes no_std for kernel or boot code or MCU boards, that's what rust-embedded is doing and I think it's fine.

many embedded boards typically have 16~64MB Flash running Linux with musl, one rust binary statically linked can easily exceeding 10MB. multi-entry is hard to manage when you have quite a few unrelated tasks, so yes I really need a true shared lib based rust for the mid-range embedded boards, which are, quite a huge number.