Does Mend Support Individual User-Specific Identification Tokens/Keys?

Yes.
Mend enables you to create individual user-specific identification tokens (userKey). The user key can be specified either in the agent configuration file or as a CLI argument when triggering a scan. By default, a user key is not required to run a scan, however, you can configure your organization's security settings to force users to provide it (in which case, without a token, the scan will fail and will not update your OSS inventory).

User Level Access Control in Integrations and APIs