Please note that the value of instance_name is entirely calculated by the specific form, so to the extend the value is ‘unique’ depends entirely on how dilligent the original form-writer was in constructing it (and in most cases its based off a UUID in any case…)
In order to ‘uniquely’ identify submissions, you first need to decide whether the id needs to be unique within a form (all versions thereof), a specific form version, all submissions from a specific device, or all submissions across all devices. Typically, if you really want to uniquely identify a specific submission (irrespective of who submitted it on what device) then you’ll have to use a UUID. UUIDs are long and ‘ugly’, but that is simply because they have to be long enough (ie enough bits) that their randomly-generated value is - statistically speaking - pretty much guaranteed never to be reproduced in your lifetime.
