In current functionality in Creo, it is not possible to auto collect user defined reps in lower level whilecreating rule based simplified rep in an asm. In the below image you can notice there is no used defined option is available.
It would be wise to have user defined option here so that rule based sim. reps in higher level asm will act dynamically based on the rules as and when adding new componets in asm.
Example: In my std components(bolts and nuts), i prepared a used defined feature called "Nothread" to exclude thread related features. So, in an asm i need to have a dynamic rule based simplified rep to show all my std components with Nothread representation. And this representation should be dynamic.