CHECKSUM for NULL START CODE?

[-dalc-]

Actually SIP packet could be the only way to provide a NULL START CODE packet validation.
Is it possible, in the neare future, to partially modify NSC packet assigning a special use to some slot in order to provide packet validation (eg: slot 1 & 2 = packet lenght, slot N & N+1 = packet checksum) ? It could make DMX more reliable at a price of few slots (eg: 4 slot loss) and mantains full compatibily with the past.

I know that slots are precious for Lighting Designers, but on the other side RDM make possible to free some tipical device control slots like "Device Reset" or "Lamp Control" or some other. (... and I think this should be tell to LDs)