Optimise WriterData cbor to exclude absent elements.
Optimise WriterData cbor to exclude absent elements.

this means the minimal writerdata has just the controller

Peergos/Peergos,Peergos/Peergos,ianopolous/Peergos,Peergos/Peergos,ianopolous/Peergos,ianopolous/Peergos