Currently if you want to make a REST API call to create or update a record in Dynamics CRM, then you need the attribute name needs to use either:
- the LogicalName for out-of-the-box attributes
- the SchemaName for custom attributes

The LogicalName and SchemaName usually only vary by case, and the APIs are case sensitive.

This SchemaName and LogicalName are elements in the EntityDefinition but unecessarily complex logic is required to select which name to use. The API should standardise on one or the other, or, even better, allow either to be used, only throwing an error if the case-insensitive version of the name would be ambiguous.