Consideration to remove IfcProductRepresentation

Description of the proposal:
IfcProductRepresentation is comprised of IfcMaterialDefinitionRepresentation and IfcProductShapeRepresentation. In a nutshell, it gives IfcMaterial and IfcProduct to reference more than one representation (style, geometry, topology) through an attribute referencing many IfcRepresentations. This attribute referencing many representations could be applied directly to IfcProduct and IfcMaterial.
Describe how it contributes to the objectives (https://github.com/buildingSMART/NextGen-IFC/wiki/Towards-a-technology-independent-IFC):
It allows for shorter geometry graphs and removes potentially unnecessary entities in the schema.
Is this a proposal to 'add', 'remove' of 'change' entities in the schema (pick one):
remove
What do we win:
clearer path to representation items from product and material
What do we lose
a reference from product definition shape to shape aspects. although the individual shape representations pertain the reference to shape aspects
Schema impact:
potentially big as it changes the concept of how products get shapes and materials get styles
Instance model impact:
simplification
Backwards compatible:
seems to be, as the attributes on IfcProductRepresentation (Name and Description) other than Representations are left empty in most if not all IFC files
Automatic migration possible:
yes, see previous point
Additional implications:

-
Note that not all points need to be satisfied!
Backwards compatibility and file size are not concerns.

Start with the proposal and the linked “Towards-a-technology-independent-IFC” objectives, then trace how IfcProductRepresentation connects IfcProduct, IfcMaterial, and IfcRepresentation. Done would require a settled schema decision plus documented effects on shape aspects, instance models, backward compatibility, and automatic migration.

Written by the indexing model from the issue text.