Extension cable for Dell TB15 docking station?

I asked this same question some time ago. It turns out that the TB15 cable is replaceable and the process is shown in the doc for it. Which would certainly indicate that they plan on having other lengths available at some point as the inside connector looks like some custom connector. That said, technically there is apparently a limitation on the cable length, I believe it is less than 3 feet. I have not found any ThunderBolt 3 extension cables.

If the max length is 3 feet, an extension cable isn't going to be much help. I thought I read that an active thunderbolt 3 cable could go 40 meters, but maybe that's just theoretical and isn't really possible.

For the time being, I'm just going to get a USB 3 hub and move that where I'd like the docking station to go. I just need the USB ports closer to my monitors, so I can plug in things like my phone, tablet, external web cam, etc.

As there aren't really a ton of Thunderbolt 3 docking station options, here's what I did which has improved the usability for me:

• I bought a USB 3 powered hub. Where I keep my laptop is about 6' from where I set. The main reason I wanted a longer cable, was to get the USB ports closer to me and where my peripherals reside. So, this resolved most of my issue.
• I set the TB16 on it's right side. This has proved to do two things:
  
  1. It's helped with the heat. The bottom of was getting very hot. Sitting it on it's side has stabilized things quite a bit for me, because the unit is able to stay cooler. I went through all this week without the USB chipset blowing up on me.
  2. It's essentially given me the ability to move the docking station a little further away, since I don't have to go over/around the docking station.

Granted, I shouldn't have to do any of this. If there was just a decently long cable, I wouldn't have had to buy the USB hub and I could have just placed the hub within reach.

OMG yes this is the worst part about the dock, once you get it working that is. why in the *** is the cord so short and not replaceable with longer lengths, or have extensions available. Kind of defeats the point of having the dock, to hide wires on my desk.

I'm also looking for an extension Thunderbolt 3 cable that would add another 18 inches to the existing cable.  So far haven't found one.  

The reason it's so short is because in order to deliver the advertised capabilities, it needs Thunderbolt 3 to operate at 40 Gbps, and the maximum lengths for a passive cable while achieving that bandwidth is 0.5m, or ~18".

And of course if Dell had made the cable detachable, people would have tried longer Thunderbolt cables and complained the dock didn't work well (or at all), and then blame the product. You can already see that in this thread, with people looking around for extension cables that would prevent their dock from working as it should. If you look around right now, you'll find that 40Gb Thunderbolt 3 cables are only 0.5m long, and even for that you'll be paying $25-30.

I agree that the length represents a major limitation, though. If I were to buy one I'd want my dock on the right as well, but since that wouldn't be possible with a laptop that has its Thunderbolt connector on the left, I might put a small platform on my desk so that I can have my laptop sitting above the dock, or possibly vice versa.

There is no such cable available, see above, due to the restrictions of 40Gb Thunderbolt 3.