Roof window blind solar or electric

We have found a satellite system installer for us.

He would also lay the 4 satellite cables through the closed roof membrane.
He says it is no problem for him (he is basically half roofer) to cut the roof membrane and reseal it.

He would reseal the roof membrane with duct tape.
Is that the correct method to reseal the cut roof membrane?

Panzerpand is certainly not the right solution. I know many people do it only with adhesive tapes (e.g. Siga). The clean and correct solution is with special fittings as already shown. You can also make the box in the ceiling on the roof slope and close it with a blind cover? What does that look like? If you work with recessed spotlights in the ceiling, it would also be an option to install only a junction box (Hensel etc.) at the end of the cable in the ceiling (do not fix the cable). Then you can always access the box through the holes of the recessed spotlights.

so you can already say that the satellite installer ("has no clue about sealing?") so you should definitely do it cleanly with the cable feed-throughs? We should possibly pressure the satellite installer to do it with the cable feed-throughs or look for another one?

Will photovoltaics also be done later with such cable feed-throughs?

You can also make the outlet in the ceiling in the roof slope and close it with a blind cover? What does that look like?

honestly, after installing the roof window blind, I would have just wallpapered over the blind cover
do you even have to access the outlet again if everything is connected correctly?

The solution with retrofitting the blinds should be simple. So that there are no complications when retrofitting.
I didn’t find the idea that the cable is right next to the window and in the worst case you can access it again from the inside bad at all.

In the end, it just has to work well and the roof has to be sealed.

Sealing is not his trade, so I wouldn’t dismiss the installer right away. He always does it that way, and in most cases, nobody cares. He simply doesn’t have any bushings and therefore doesn’t use any. The bushing costs about 2€ I think (but everything is a bit more expensive nowadays). Just order a few privately and provide them to the installer. It will cost you 20€.

Sealing with adhesive tapes also works but not properly, and if it is done in an emergency (because no bushing is available or it’s not possible with a bushing) then it should be done with the proper adhesive tapes.

Of course, you can put the box in the roof and wallpaper over it. Normally, you never have to touch it again; the lifespan of the roller shutter motors is pretty good (they don’t like quick starts and freezing solid). You will always see the imprint of the blind cover, even if you recess it (there is a special tool for that). I would solve it differently in a new building.

He must also be able to use the cable entry sleeve properly.

If he has never done it that way before, then his solution would probably be better (what he is practiced in).

Can you explain your solution again on how to do it optimally?
Without much effort? So that anyone can practically do it?

The optimal solution was mentioned to you above. It really is no rocket science to stick a glue sleeve around a cable. We, as laymen, have already done this several times in our house. No problems. Panzertape is not suitable for this.