Why is ground wire long and thick

Draw in the ground wire later

uff ...
... I can’t say whether that’s a mess or not. why can't you pull a ground wire? how thick is the pipe diameter? A good, patient electrician gets six 1.5mm2 wires into a 20mm hose. well
So no grounding at all is grossly negligent and well, I don't want to comment on it.
In fact, there could be 1 reason why it is not as clean as if all the lines were installed in a pipe from the start. namely because of the different circuits. do you have terrace light and all roller blind motors on the same circuit? probably not. but now want to hang everything on the 1.5mm² pe conductor from the terrace light ... and so your pe conductor is undersized ...
solution: increase the cross-section or remove an associated pe conductor with the same cross-section for each extra circuit. @...
PE conductor undersized?
yes but only if there is something on both circles and that is very unlikely and at full power, too.
a 1.5m2 creates up to 16A!

so better later and not quite right than never, although this solution is still not allowed.

lg

therefore
I wrote there could be a reason clear only with 2 or more failures .... this solution is already feasible but if he asks if it is correct, then that is unfortunately the answer.
according to your method the probability could also go up with 2.5mm² on your distribution. Electric wire?
Did you pull individual wires to the blinds? That is also quite unusual, normally a three-pole cable is used (only this one gets tight on the plug, and this connection should be waterproof.

Why can't the PE leader follow suit? Pull out existing wires, pulling in the pull-in spring at the same time (tie at one end), pull in the PE conductor again. Should be done in 10 minutes / roller blind.

I would not engage in any experiments here. .. absolutely 1xPE connection per roller shutter, in the same pipe as the supply line. (if this is connected somewhere else (e.g. outside lamp) and you dismantle it after years and forget about the proper connection ...) As long as nothing happens, no problem, but if you should harm a person because of your botch, then you are faced with the Kadi. (or your electrician who gave you the stamp for the completion.) answer
Hello!

The whole thing is not done in 10 minutes, because we had already sealed the pipes on the outside with foam (since we are building windproof, this was advised to us). on the first floor we got through all the shutters. I would now only connect 5 shutters to a grounding (attic light) on the upper floor. It is clear to me that the whole thing is not optimal. But I think it's better than nothing.

greetings
Martin Foam?
Sealing with foam? Aha. I would question the advisor ...

anyway. any ground (attic light) is better than no ground ...
....
sending out foam is already ok if you ensure that you are already tight inside the pipe that goes out of the can. otherwise you have the problem of condensation in the pipe. Foam is not ok
exactly for the reason Martin described: you can't get him out. Usually you put a (silicone) plug about 1-2cm long, which I can plug out again with a sharp screwdriver. Foam, on the other hand, creeps 30 cm into the pipe, if you want to repair something, then good night.

@benji
Yes, as far as the removal is concerned, I agree with you, of course, I only put removable insulating stuff in from the outside.
but if you only seal with silicone on the outside, you have condensation in the pipe when the warm air creeps into the pipe and then cools down.
always according to the motto inside closer than outside that's what I wanted to get at.