Part Configuration and Instance - Instance allocation in a multi-level structure

Hello, I need additional information to those available in the Help Center documentation for Part Configuration and Instance.

Windchill 12.0.2.8

When allocating child Instance in a Parent Instance Structure, it is OK to have Untraced sublevel BOM containing child with Trace Code Serial Number or Lot which will be allocated from this Parent Instance ?

It seems that this is possible but it is recommended ?

In our case, these untraced level in the Manufacturing BOM Structure are like Gathering Part, it correspondent to intermediate advancement of the assembly, not item in stock.

For me it is OK until these untraced sub-levels have a quantity of one, if up to one, there is a problem to link child occurrence with Reference Designator (Position in the product).

What is your point of view ?

Thanks