It isn't clear why DeviceDefinition has specialization 0..* RelatedArtifact, yet Device has a {{specialization }}Backbone element  with three sub-elements. I would assume that the requirements are the same for both. The two should be aligned.

Other elements that should be considered for alignment:

• {{description }}(only present in DeviceDefinition)
• manufacturer/partNumber (order differs)
• {{modelNumber }}(ensure consistency for short and descriptions)
• hasPart/parentDevice/parent (why do we have multiple approaches to the hierarchy, even within the same resource? parentDevice/parent name should be same)
• languageCode }}(missing in {{{}Device. Also, why include "Code" in name?)
• property.type (bind to the same valueset, use same long/short definitions)
• {{property.value[x] }}(use same long/short definitions)

Also, consider aligning element order, e.g. manufacturer, partNumber, safety.