Setting IsNotNavigable() on a navigation property should also set IsNotFilterable() and IsUnsortable() however, if you define a model with customers, related orders and related credit score, and you make the Orders and CreditScore navigation properties not navigable, you can still filter and sort over the properties of the related entities using queries like this one:
/odata/QueryLimitCustomers?$filter=Orders/any(o: o/Id eq 5)
/odata/QueryLimitCustomers?$filter=CreditScore/CreditScore eq 100
/odata/QueryLimitCustomers?$orderby=CreditScore/CreditScore desc
/odata/QueryLimitCustomers?$filter=Orders/any(o: o/Id eq 5)
/odata/QueryLimitCustomers?$filter=CreditScore/CreditScore eq 100
/odata/QueryLimitCustomers?$orderby=CreditScore/CreditScore desc