delete log & guest info

Hi all

I want to give access to external user with guest access : this part is ok and working fine

I also want to log what they do and keep logs for 365 days : ok 

I'm using 100D 5.2.2 with Faz 5.4.0

But...

If expired user is purged/deleted, is there a way to keep all information related to this user (username, tel, company, mail,...) if there is there is still logs matching this user ?

All user information are in logs when user is created, and only on this log entry

An exemple :

(logs are deleted after 365 days)

I create today a guest user who is active 8 hour after first login.

This account is used 6 months after.

7 months later, I can access to his logs, but will I be able to know who he is (get user information)

Is there a way to achieved this ?