SPEAKERS JUMPER CABLES

I think only one person touched on this so far: experimenting with the connection orientation yields different audible results that are pretty straightforward in my experience.
Connect to lower terminals and jump to upper.
Connect to upper terminals and jump to lower.
Connect diagonally; + lower, - upper, then jumper to corresponding post.
As they say, YMMV; I would imagine the crossover topology will affect your sonic outcome. I recently bought a pair of single binding post speakers (Spatial M3 Turbo S), and it’s one less thing to make myself crazy over.

"Does anyone sell directional (arrows) jumper cables? Audioquest? Anyone? I don’t wish to put some piece of junk there."

Yes - Paul Speltz of Anticables makes a jumper which is directional.

In my case only "one" jumper on the (-) have the better performance, in my bi wired speaker cable.

I tried jumpers in various fashion as @james_edward  stated and as @almarg recommended as well for my JBL 4319 monitors and it ended up sounding best the way JBL recommends: jumping from the lower to the upper posts.

I've read where that's the preferred way for a three way, or larger speaker and to jump from the top, down, with a two-way design. You'll never know until your try all the different ways.

All the best,
Nonoise

Has anyone experienced using 9999 Pure Silver Wire 12 Gauge as jumpers?
Pro's and con's?