Both IFC and COBie spreadsheet are not “static” and most of the times, COBie spreadsheet doesn’t use just as an archive (which the input data just comes from IFC file)
For this reason “you have to have a mechanism to archive changes inside the spreadsheet”
IFC has IfcOwnerHistory yes, but as you mentioned nobody uses it and even bSI is thinking to drop it. But I think it’s useful, especially after ISO 19650 which mainly focuses on legal aspects, so owner and owner history becomes important
Also, take a look at IfcOwnerHistory it doesn’t have any “logic” to archive “all” changes, it just provides the last change
About the feature that adds custom columns, I think it would be really useful
I saw you work on an invaluable idea to be able to generate “custom MVDs = MicroMVDs”