How is the POS Device ID generated in Shopify UI Extensions?

[timvdam]

Its possible to get a Device ID within Shopify POS UI Extensions (https://shopify.dev/docs/api/pos-extensions/ui-extensions-reference/api/device), but there is no information on where this ID comes from. I compared this ID to all IDs listed on my iPad settings' About page but could not find it (even tried different encodings). I'm guessing this device ID may be a combination of the actual Device ID and an App ID (eg like this https://shopify.dev/docs/api/app-bridge/previous-versions/actions/pos#device-payload). Is it save to assume this device ID never changes, even across different app versions, etc?