This will be amazingly impressive if the new Ladelux can really draw up to 12 watts from the hub and put it to good use. I assume the link below is what you saw.
https://nabendynamo.de/en/products/ladelux/
The Forumslader (spell?) is a high power USB charging unit, but I think it has less power than that. A few years ago I think that Gauvins on this forum used one of those USB chargers. If I recall correctly, he could feel the extra drag when riding and charging batteries with that unit.
I use the Cycle2Charge V3 USB charger which has an output significantly less than that. I can't feel the drag, but I know there is additional drag when I am charging batteries. The output curve is at this link, the green line on the graph at the link is the V3.
https://www.cycle2charge.de/index.php/en/
I think I got slightly less output than the graph claims, but it is more output than the Sinewave Revolution that I used to use.
At my normal touring speed on flatter ground, I am looking at about 2.5 watts of output with the Cycle2Charge V3. Photo below is from my most recent tour that I got home from a few weeks ago, I tried to take some photos of the volt/amp meter plugged into the Cycle2Charge, photo shows a reading (red LED) of 0.44 amps, which would be a hair under 2.5 watts. This USB charger only works with the lights off. In this case, the power was going into my powerbank which functioned as a pass through cache battery inside my handlebar bag. My cycle computer says I was doing 9 mph in the photo.
I never had to plug into an outlet on this tour. The dynohub (Shimano, do not recall the number), the Cycle2Charge USB charger, and the pass through cache battery (Voltaic power bank) took care of my needs. The Voltaic always had three or four bars for power, so it met my needs quite well for this tour of 660 miles.
That said, the phone was off almost all the time unless I was using it. But I accidently had it on for one full day without realizing it. GPS and camera batteries consumed most of the power that I generated from the hub. There were three days where I had my dyno powered lights on for part or all of the day, at those times I was not charging batteries. Those lights were typically off, but there were a few times when I wanted the additional visibility of the extra lights, and one day I rode past sunset and needed the lighting. That said, the vast majority of the miles were charging batteries with lights off. I almost always had a taillight powered by a pair of AAA rechargeable NiMH batteries in flash mode.
I got lucky to get that photo, I could not see what I was doing when I was taking lots of photos hoping I would get one of the meter output since I had to keep my eyes on the road at the time I was trying to get the photo of what was going on under my GPS and handlebar. Most of my photos had the camera aimed the wrong way.