I just spliced them yesterday. I got an instruction manual from RS for this.
https://www.rssailingstore.com/files//4385ebcf-86f7-46ae-996c-a99200cf4aee/Aero%20instructions%20-%20OVER%20DECK%20CONTROL%20LINES%20(ROOSTER).pdf
In the guide v6 it is not explained, how to splice it. My guide ha the name "Over Deck Control Lines V2"
I would also prefer splicing.