@Igor Kudryk 1. This is the minor question but still would be good to know. So, when in one SF org we populate external id of SF record from another org, is there any difference between putting 15-digits vs 18-digits Id? (In case this Id will be further used somewhere in the logic) From what I see it puts 18-digits Id by default. 2. Another thing, it's not the question, it's more my finding. There is another benefit of using new Named Credentials (External Credential & Named Credentials): As you said, one External Credential can be used in multiple Named Credentials. If you set Custom Header on External Credential level - this header will be applied to all Named Credentials that use that External Credential. But in other hand you can overwrite/add additional custom header to specific Named Credential if needed. Of course, it's not important in our case, but it might be useful in some more advanced integrations with multiple different callouts.