I got what I wanted.

I've been thinking a lot whether I should use the Manfrotto 026 Lite-Tite or about 10 cheaper "Phottix Varos BG II".
The main difference is, as previously mentioned in the reviews before, the fact that one has the opportunity at Phottix, the flash near and along to mount the screen shaft (places for a reasonable installation probably too close to the stem). This option does not offer the Manfrotto Neiger. For the hole to shield assembly is drilled slightly oblique, thus the flash but then centered on the screen can meet. In order to fix the supposed "mounting shortcoming", I got me another Walimex mini ball head to be free in the assembly.

Ichwollte the differences in flash assembly to try along the umbrella shaft axis and normal flash mounting only with hot shoe and evaluate safe accordingly.
Hence the attached picture has emerged.

With my body (especially with this screen), the Assembly makes the screen along the shaft axis no sense. The illumination is in standard mounting and 24mm Flash Focal Length + lens - evenly on - as can be seen.

Incidentally, I know quite a meaning behind why 4 different screws / bolts handles were used: Thus, less likelihood of confusion when setting - especially if you only want to correct slightly, it's annoying when you turn in the wrong screw and half system out of balance.

Conclusion:
I am completely satisfied with the screen Eiger MA 026 Lite-Tite Manfrotto. The build quality is excellent. The whole system is stable. Everything just hervorraend how I expected it. It will find its way into my Fotokiste more Neiger.

Note: The considerations on my part to Phottix Panhead are purely theoretical, since I did not possess it. I base it on the product information and reviews about this product here on Amazon.