REST-API - Can't upload to file-field on products identified by UUID

[OhLookAUser]

When developing a solution using the Akeneo REST-API, I had problems uploading a file to a file-field on a product, that is identified by a UUID.

According to the documentation, the API-endpoint expects a property "identifier" (when uploading to a "product") or "code" (when uploading to a "product_model").
Unfortunately, the product (type "product") I was trying to adress, doesn't have an attribute "identifier"; only a "uuid".
So when sending the UUID as identifier, Akeneo can't match it with any products and replies with an error-code (I believe it was 422).
"product": {"identifier":"{uuid}","attribute":"{myField}","locale":"{myLocale}","scope":null}
Sending the payload with a property "uuid" is not supported.
"product": {"uuid":"{uuid}","attribute":"{myField}","locale":"{myLocale}","scope":null}

Could this be caused by the logic of the endpoint (it seems to search a product by looking at the "identifier"-attribute, even if the product doesn't have that; but instead has the "uuid"-attribute)?
And might it be related to the way product identifiers are setup in the installed Akeneo-system? The system I tested with, might have been setup to use UUIDs as identifiers at install, so products don't seem to have an attribute "identifier" while other, (possibly older) systems might be setup to use "identifier" as the actual identifier with UUIDs being retrofitted, so both attributes ("identifier" and "uuid") exist on products?

Currently my workaround is to upload to the file to an asset, as linking an asset to an attribute of UUID-products seems to be working.

[OhLookAUser]

Additional note:
This gap in functionality might become visible by looking at the API-docs already, as there are endpoints for interacting with "Product (uuid)", Product (identifier)" and Product model, while in the description for Product media file-upload, only "product" and "product_model" are mentioned.