One user, EcleX, has reported that the first release version of Alifix is incredibly slow at dealing with old (pre-Sierra) broken Finder Aliases. There doesn’t appear to be any user workaround for this: if you have old aliases which point to previous volumes, then macOS takes minutes trying to resolve each one, and may display dialogs and alerts in the process.
Alifix 1.1 attempts to address this issue by blocking all user interaction when trying to resolve aliases, and by ignoring volumes which aren’t currently mounted rather than trying to find them. I hope therefore that it will scan much quicker when it is tackling old and broken aliases. I’m sure that you’ll let me know if this succeeds.