When justifying changes to GSIM, I would find it very useful to understand how the proposed objects relate not just to other GSIM objects, but also to GSBPM sub-processes (as per the diagram below, from the GSIM documentation). This will help make it clear how the object will be used in statistical processes. If an object can not be related to any GSBPM sub-process, I would suggest that it is not a candidate for inclusion in GSIM.