When using 2.5mm twin-and-earth cable, and where two wires go into one
terminal on the back of a socket, should the two bare wire ends be twisted
together?

I have read Google sources that think twisting weakens the wire, and say,
e.g. "Insert wires fully into their terminals. Don't twist two or more wires
together".

A different Google source says "Taking the conductors, twist each together
.... now insert the pairs of conductors into the correspondingly labelled
terminal".

Socket manufacturers such as MK have nothing to say on this matter in their
installation instruction sheets.

What is good practice, should the wires be twisted, or not twisted?