Detecting whether an order was created by the shop owner

[ShopDoctors]

Hello everyone. We have a few apps which are subscribed to the "orders/create" webhook topic: https://shopify.dev/docs/api/admin-rest/2023-01/resources/webhook#event-topics-orders-create

What we are trying to do with the data ranges from reporting to fraud detection. The problem we are facing is that there doesn't seem to be a way to 100% surely identify orders which were created by the shop owner.

Here's what we've tried so far:

1. We check the 'gateway' property and if we see value 'manual' then we know it's an owner-created order. This unfortunately does not identify all of them.

2. We check the 'processing_method' property and we noticed that most manual orders had either an empty string (''), or 'manual' in the value. The problem is shops in India which use Cash on delivery also use 'manual' method.

3. We change the 'source_name' and we noticed that manual orders that start as draft order have the value 'shopify_draft_order'. The problem is that orders created by some apps (not all) also show the same value.

4. We see that there is a 'source_identifier' property which can have a numeric value or a random string value, but we can't find documentation that would help us use this to identify manually created orders.

Any ideas/suggestions would be much appreciated!