Y adaptor for 2 bulbs in celing pendant lampholder?

Isn't the notion of using live mains-carrying uninsulated copper wire (at the bulbholder terminals) to provide physical support just a bit more risky than it needs to be?

What about the "bodge factor"?

In other words, when the insulation is cut off one of the cores, some strands will also be cut. Mr Average will cut more than Mr Professional.

But the infamous Mr Half-Asleep will cut more strands off than Mr Average. Mr Half-Asleep might cut as many as a third of the strands and still think he has done a good job.

Then Mr Half-Asleep gives a simple twist to the remaining filaments and shoves them into the brass electrical conductor and screws it down.

Some of his filaments ....

... never go under the screw. ... get completely severed by over-tightening the screw. ... get damaged but not severed from the over-tightening. ... might get charred over time with use.

So the "bodge factor" (or "real life" if you prefer) may reduce the cross-sectional area of the copper by, well, who knows? We may end up with only a fraction of what we started with.

The same sort of thing happens all the time - on power pylons.

Yes. And with suitable design precautions taken when designing pylons and their wires. With only professionls allowed to mess with them.

OTOH I am talking about Joe Soap and domestic use.

Good old Joe may see a very heavy lampshade (intended for a standard lamp) and think it must also be ok on his home-installed lampholder. It could be too heavy. And in this case we are talking about potentially dangerous mains electricity.

Much ado about nothing where most of us are concerned.

You'll never prevent stupidity though you sound like someone who should not be attempting DIY.

Joe Soap is the character. I am real. Don't mix us up!