is it common to proxy register route objects for the purpose of grouping them for use in an as-set

Greeting, One of the DDoS mitigation providers we work with creates proxy route objects for its customers’ prefixes. These route objects specify a common origin ASN rather than the actual origin ASN that would be seen in routing tables. Their rationale is to bind the prefixes to a single ASN, allowing the entire set of customer routes to be announced via an as-set. Is this a common approach? Just curious. thanks, steve Steven Wallace Director - Routing Integrity Internet2 ssw@internet2.edu