Limit element creation using reference types

I’m designing an AF database where we want most things to be correctly set up and planned on the template side, so that end-users can create the AF content later. One of the functionalities I use is creating my own reference types i PI System Explorer, and it works as expected when I define that elements from TemplateB can only be created below elements from TemplateA. Example: I want to make sure that the only element below “Oil Well with MPFM” is the actual “MPFM”. I want to make sure that AF designers follow the rules I've set, to keep the integrity of the structure. Both for referencing the child element (in the parent template), and also for rollup analyses in other structuring elements where my elements are referenced. As of today, when users create new child elements below elements where reference types are defined, they can easily scroll past the custom reference types and select the fundamental reference types - ignoring all the know-how and though I've put in.