Easier said than done.

If you have to support the sort of user that barely managed to download a copy of putty a few years ago and kept using this, then walking them through key generation and use is a nightmare.

One could fairly argue that maybe such people shouldn't have access to a system, but it is a reality.

Of course the likelihood that a system using musl is something that class of user would be accessing is lower.

Maybe now that ssh is generally "just there" for Windows users, you can more easily work with them to generate a key, or give them a zip file to make them have a key in a standard way. But the interaction of ssh and windows file security can be... Interesting, though mostly an issue on the ash server side.

The vuln is specifically for key-based accounts:

Second, the target system account must be configured to be passwordless. Passwordless accounts are commonly used for accounts that use certificate-based authentication.

For added security, there is a pam module for 6-digit OTP