...there's a little play between the chainrings and the spider...

This never goes to the better, you should fix that 

The anti-dumping charge should only be added to complete bikes from China, not parts.

That's right, you can import separate carbon parts, frames(unpainted) and rims, no problem.
The anti-dumping is about steel and aluminum, and since most painted frames are from these materials, even if they are carbon, they fall into the anti-dumping category. Don't try to understand...
Many bike shops and small builders are exempted, I tried to find the way to get an exemption but gave up.

A friend bought a frame, got the anti-dumping, paid it. I told him to complain as it was unpainted(clear coat, but it was disputable).
He provided all the proofs. But the pesky guy on the other side said: nothing proves the frame he's showing to them now was the one in the box 

Thank you! I was looking at that one. Did you use it with one of the install tools they sell on Aliexpress?

I had a used tool from Wheels MFG for years in the workshop, but I didn't know what it was for.
One day, I found out it had exactly the right diameters to hammer out the bushings from shocks.
Then I use my usual hub press to gently install the bearing into the shock.

Google for any brand with the words "exploded rim" and you'll find some.
Personally I've seen Bontrager and Roval similarly exploded wheels, as well as some of the lightbicycle ones I helped to buy.
It happens, it is the way carbon fails. The most important is the warranty you get when this happens.
All the brand above honor it.
Looking forward to see how Ryet is reacting to that.

Ask Carbonda, I think the 505SL has Udh. In another forum someone also reported about a 707 with Udh.

Yes it is UDH, I'm still waiting some parts for a first over 3 coming builds.
All with a GX T-type rear + Force transmission 1x

I'm curious about your opinion and recommendations on Press-Fit vs Thread-Together BB86 bottom bracket shells and especially these two in particular:

• ZTTO Thread Together - https://www.aliexpress.com/item/1005005940645297.html
• Shimano Dura Ace SM-BB92-41B - About 20€ in a local shop

Which one would you pick and why?

The thread together ZTTO BBs I tried were great; however, for that price, don't expect to get quality bearings.
You can replace the bearings with better ones. However, one hard issue, especially in the DUB world, is finding replacement plastic sleeves if you crush them. I'm a tinkerer, so it's fine for me, but if you're not, I would recommend the Shimano one.
If installed correctly with a compound to help it adhere to the frame, it should be reliable for many thousands of kilometers/miles.

Still riding the wheelset of my first build, 9+ years ago, on my second/winter hardtail.
And with Pilar nipples and aero spokes !

I've had a few friends who did break their rim while riding, or were hit by a car, or melt their brake pad into the rim while descending mountains,...
Clearly not product faults.
But LB did always send me a free replacement rim, us paying the shipping.

Their new carbon spokes make stiff and light wheels.
As said many times already in the forum... yes, I'm a fan