When the IME inserts the character, it'll be made up of multiple bytes because of the nature of UTF-8, so it may appear as multiple asterisks regardless.
At the very least, all GNU tools put a lot of focus on localization support, and I hope sudo-rs is the same.
Hmmm, hopefully sudo-rs respects LC* env vars. I recall reading a few years back that some Rust Unix tools skipped that and won big on benchmarks until folks realized they weren’t handling NC localization properly.