Should I use ECC RAM for a home Unraid NAS?

Probably not worth it. Unraid already handles bitrot with parity and file checksums, and ECC RAM won’t make your data safer in the way you think. For a home media server or backup box, the odds of a silent RAM error corrupting your files are tiny. A good backup strategy (3-2-1) and Unraid’s parity are plenty for most users.