I’ll just throw in my two cents argument for UUID. I have a sheet of students. When a new name is entered, I have a script the takes over and populates 3 other sheets with their name. Their name is the key value which links the sheets together. The problem I have is that if a name is ever changed, or it was misspelled and corrected, then a new entry is created in those other tables and and the link to any previously entered data is broken. For me, UUID would allow one ID and it frees me up to changes the students name without breaking any links to data in other sheets.