Safety Stock using IO in CTO environment

Hi ,
We are using IO for generating Safety stock for bought items, IO does not seem to generate reasonable SS for components and is not consistent either.

So, looking for expert help on standard behavior in our case. Let us take below scenario:

1) We have a sales inventory org US1 (Ship from) and manufacturing Org US2 (Make at)
2) Model M1 has an option O1 with effective planning percentages of 100% w.r.t. Model M1
So, commoned BOM structure:
M1
|_ OC1
        |__O1

3) We have weekly forecast for M1 in US1. 
4) We have Sourcing rule for model M1 between US1 to source from org US2