The IDA shows Hardware Developers registering devices. There is a picture and text showing how they get IDs from the IDA and register them with a Data Engine.
The MMI makes it clear that only a Service Provider can register devices and that once registered, they are associated with that Service Provider.
The RPE shows that almost all of the actors can take the HD role: Thus a DE can also be a HD, but then how can it manufacture IoT devices with IDs since they have to be identified with a known SP and DE.
How will this work in practice? How will a HD programme devices with a unique ID before deciding what Service Provider to sell/distribute them to?