Security Limitations Re: Azure B2C

I wanted to know the key differences in security between Entra External IDs and Azure B2C.

I know several of them so far such as Defender for Cloud is not supported by AB2C and several of the sign in risks (and all user risk) detections are not available as well as stated here:

learn.microsoft.com/en-us/azure/active-directory-b2c/conditional-access-identity-protection-overview

The one question I need a firm answer on is whether a AB2C user sign in logs can be attributed to a user. The following article leaves me with confusion:

learn.microsoft.com/en-us/azure/active-directory-b2c/view-audit-logs

My question is this, (1) by what way(s) can you attribute a sign in in AB2C and Entra External IDs to a user account, and (2) what are the differences in all log events for them both as well.

-Thank you in advance!