fix(user migration): adding to auto vs guided

src/content/docs/accounts/original-accounts-billing/original-users-roles/user-migration.mdx

@@ -109,7 +109,10 @@ Here are some tips about using the first page:
   src={userMigrationPage2}
 />
 
-You may choose a) a guided setup that allows more configuration options, or b) an automatic setup with fewer steps. If you are not using SAML SSO or SCIM, and are okay giving all of your migrated users access to all accounts, we recommend using the automatic setup option. (Note that you can always do more partitioning of user access to accounts later.)
+You may choose a) a guided setup that allows more configuration options, or b) an automatic setup with fewer steps. Some tips on choosing this: 
+
+* If you're not using SAML SSO or SCIM for the users you're migrating, and are okay giving all of your migrated users access to all accounts, we recommend using the automatic setup option. (Note that you can always do more partitioning of user access to accounts later.)
+* Note that once your users are migrated, they reside in a specific authentication domain that governs how they're managed in New Relic (via New Relic versus via an IDP) and how they log in (manual login versus SAML SSO), and these settings can't be changed once users are added to an authentication domain. One implication of this is that you wouldn't be able to migrate your users to a default authentication domain (New Relic-managed, with manual login) and then later manage those same user records via SCIM provisioning: in that case, you'd need to create a new authentication domain with new user records. 
 
 ## Step 3: Name your organization [#page3]