Hi Dave, sorry to be confusing I had just come down with man flu and wasn't following correct forum etiquette by not quoting the OP.Hi Blue Duck,
Your question to me is academic, since I don't do 17th Edition Split Boards.
If I did, I would use part L/H labels and part R/H labels, which would work OK.
If RCD labels were required, I could produce them quite easily.
Not only can I supply DBs to your specification, I can supply the labels to your spec.as well.