I have a full answer to this, but TL:DR AutoHold is a game-changer on this issue and my car doesn't have it.
That said....
As I'm sure you know, the DSG is a dual clutch gearbox that operates automatically. It's far different to a traditional automatic gearbox.
While the DSG offers the convenience of a traditional automatic, with improved fuel economy and the ability to shift gears more quickly than a manual gearbox, it has the same basic operation as a traditional gearbox, though with two clutches and two banks of gears.
Gears 1, 3, 5, (and maybe 7) on one bank, and gears 2, 4, 6 (and maybe 8 ) on the other. Pre-selecting the next gear with the clutch disengaged on the other bank of gears to the one in use with the clutch engaged, is what gives the DSG its speed advantage.
To change gear, the active bank disengages its clutch, and at almost precisely the same time, the inactive bank engages its clutch and the car has changed gear.
The DQ381 gearbox and manual handbrake set-up on my 2019 car is not one of the very latest gearboxes, and so it still needs to be driven with some of the considerations that should be would used when driving a manual gearbox.
I suspect the newer gearboxes featuring electronic handbrakes with AutoHold really do not need to be taken out of drive mode when at the lights, and are perfectly happy sat there for some time with the clutch completely disengaged.
As I indicated originally, my gearbox does not completely disengage the clutch when stationary in drive.
The Octavia manual does not need to change, because it tells drivers what they may do, without prescriptively telling them what they should do.
So for me "The selector lever position N does not have to be selected if stopping for a short time, such as at cross roads." means "Don't worry about burning out the clutch on the 1,3,5,7 bank of gears waiting at a junction in drive, so long as you're only going to be riding the clutch for a short time."
For cars with AutoHold, "The selector lever position N does not have to be selected if stopping for a short time, such as at cross roads." means "Don't worry about burning out the clutch because you can't, but it's probably a good idea for road safety to put the car in neutral and bung the handbrake on if you're going to be sat for a while."
On mine, the gear selector and handbrake are big levers that invite use.
On the cars with electronic handbrakes and AutoHold, the gear selector and handbrake controls are reduced to switches, which are not intended to be used in the same way, because they don't need to need to be.
AutoHold does automatically what I have to do manually. As I seem to be getting a hint of rheumatism in my elbow, if that gets much worse, I may start to think of electronic handbrakes and AutoHold as very good ideas.
In summary, I suspect a few of us have been talking at cross purposes here, without fully understanding the intricacies of the vehicles involved. I certainly didn't know about AutoHold at the start of this thread.
There have probably been a few people who understood the difference between cars with and without AutoHold, who were wondering what we were arguing about.
Oh well, hopefully this thread has shed some light on the issue and we managed to do it without anyone getting angry about it. Lovely! 😊