I am installing some architrave power sockets into a garage ceiling, so I have flexibility to move light fixtures around.
Country is New Zealand, and the line voltage specs are 230V AC 50 HZ.
I have run 1.5mm2 cable, but there are points where I want one socket to have two wires, an incoming and an outgoing.
I have been using the correct size ferrule, but now I want to put two wires under one screw.
Do I put two wires into one larger ferrule?

OR Do I put two ferrules under one screw?

Wire nuts are not an option here - I could pigtail out to a three-way joiner, but that needs its own junction box.
What's the best way to do this? Extension question, what if there were more-than-two wires coming to the same point?