E-Notebook Enterprise: ELN requires a minimum of 3 characters for Login ID, Can this be changed to 1 or 2 characters?

Unfortunately, we can't change minimal user name length to 1 or 2 characters. One of the features that E-Notebook provides is "Title 21 CFR Part 11 compliance".
At this time, we can't change core code to allow less letters without introducing risk to your organization and other customers requiring this compliance.