TB16 support - any improvement over the last year?

I purchased a XPS13 developer edition some 18 month ago. The system is ok, I used it on a daily base. 

Unfortunately I also purchased a TB16 dock shortly afterwards relying on the Dell statement and advertising claiming that it works with the developer systems. 

It was painful to find out that this is simply not true. As many many others I had a frustrating journey, enduring support getting worse with every BIOS upgrade, frequent issues with USB, ethernet, sounds and most of all displays. In difference to others I was very stupid and did NOT return the unit but again relied on the claims of Dell support members that the issue will get resolved and that "a team" is working on the support. 

The results that "team" created over the following month? None. 

Now another year has gone by, the issues again got worse with the last upgrade to BIOS 2.8.1. Naiv as I am I thought I'd give it another chance. And that a company like Dell should be able to solve such issues. Of course I was wrong and made the same experience as before: the issues got worse with the upgrade. Now my external monitor is not reliably usable at all any more. How frustrating for such an expensive piece of hardware. Especially since it (still) is explicitly recommended by Dell for those systems despite the fact that the company fails to solve the major issues. 

For me the external monitor (a Dell monitor...) comes alive when booting, for every 5th to 10th attempt it even shows the login screen to my system. But the, when the X server gets started things go dark. That happened now and then month ago, I had to "reboot" the monitor to have it pick up the signal again. But that does not work after the upgrade any more. I tried two other monitors (other companies: exactly the same behavior. I tried another XPS system with the same dock: exactly the same behavior. So it is the dock that is causing the issues. Today I even tried a brand new replacement dock I ordered. And guess what? Exactly the same issues. So Dell has NOT been able to solve the issue, not even after 2 years. Instead they STILL sell the units, recommend them officially.

I can and will return the new dock tomorrow. But of course I can not return the original dock which Dell never got to work. And I was stupid enough to listen to the Dell support members and wait. Shaking my head now about that...

So my question: 

Anyone has another story with their TB16? Maybe I missed something that people found out over the last months?