The intention is to have the inspection results at loading port (vs discharge port). Hence I have no problem to accept this document evenso not litterally issued at loading port

The statement ''to be presented within l/c validity'' is in itself a non-sence since documents presented outside l/c validity are not acceptable anyhow. I think that the issuing bank must be more pricise on it's terms. I always require clarification.

I see no problem for the second confirming bank to book the engagement under the first confirming bank. The difference in confirming i/o issuing a IRU might be that the engaging bank likes/must know the underlying transaction.