Think about it...
That given resistance is based on the length and width of that mesh.
So, if you cut it in half, what do you think happens?

If I have a dual coil atty & I put 2 coils in (parallel like most are) with an ohm reading of 0.2 ohm, then remove 1 of the coils, I'd expect a reading of 0.4 ohm.
So Similarly, I'd expect to see the mesh strip double in ohms when cut in half & just 1 half used.

However, that still isn't answering my question.
Specifically, I'm interested to know if anyone has tried this & if there are any issues that arise from doing it.

You need to think about it, the man is saying cutting it in half long ways (length the same and half the width) which should double the resistance, same as going up in gauge of wire; not cut into two half short pieces, which would half the resistance like cutting the wire into half it’s original length.
Less width= higher resistance
Less length = lower

Possibly it would but you'd still have the same amount of metal & thus the same resistance, just that now it would be more brittle & likely not to last as long on the atty.

I would think these would be thin enough already & thin enough that a good sharp pair of scissors could easily cut them into half the width, with maybe using wire cutters on the thicker end pieces of the mesh.
Placing the strip in a vice may help make the cut more accurate but I don't see there being any other advantage to using the vice.

I would be very interested to know your results if you do try halving the strips. I would think that you'd need to run them at lower wattage, perhaps 40-50w would be optimal, rather than 60-70w.