Caveat: This assumes that when you are saying "KDC SET" that it is the SET for **ALL** KDCs in the domain. Otherwise a renewal may go to a KDC that doesn't support that etype.
Is this a request for a TGT? If yes then the supported encryption types (SET) will be reduced.
Is this a request for a subsession key? If yes then the KDC SET is irrelevant.