On balance, we agree this it is reasonable given the need to take explicit account of underwriting standards.
We do not regard the bank's underwriting standards to be a significant determinant of the default or loss in default behavior of large corporate borrowers. Hence, it does not appear important to preclude use of the rating system that the bank already has implemented for such borrowers.
The issues of control and ownership are important for receivables purchased from non-financial counter-parties. We understand the need to reinterpret these rules to be consistent with the nature of securitisation exposures. But we do not see why they should preclude use of a PuRA model and hence the SEC-IRBA for synthetic deals.
We believe that the implications of the inversion of the usual data hierarchy should be more explicitly spelt out. This point is explained in our attached paper.
We think they are broadly workable.
We have written a paper explaining how we believe the RTS should be extended to cover several issues relevant for empirical modellers implementing PuRA models.