Unable to show a simplified part in the assembly.
When a part is modified by an assembly feature, simplification is not allowed.
The reason for this behavior is due to how assembly features work...
Assembly features modify parts in the assembly but not in the actual part file.
To achieve this behavior, we actually copy the solid body of the part and
embed it into the assembly, also referred to as an override body.
Notes and References
OS Version: 1064