Using Repeat region/Column Rep for bom has never functioned as I thought it should since it was introduced a long time ago.
This where you have an assembly and have varying configurations. Like xxx-1, xxx-2, etc. There would be columns added to qty bom. In each qty you can use Repeat region/Column Rep to assign a model to each column and output its own qtys. The bom would section off each "-" (dash) number. You specifiy, no duplicates in Repeat region/attributes. It combines as attached. Works great. However...you can not show balloons. For discussion below let's consider this the "main" bom.
Our work around:
Do same as described above. Add -1 view. Add another bom. Show balloons for new bom on -1. Fix all rows to match main bom. Repeat for -2. Optional: Fix all rows of main bom.
Now if there is new design activity, add, subtracting items, this all runs into issues. In my case I unfixed the boms and repeated steps above. So, it works, but it requires finesse.
I attempted to test, if in 6.0 Column Model/Rep was improved. I was disappointed. Unless, perhaps I am missing something. Or is it really still half baked? Anyone work with multiple assembly configuration boms?