Here's an update, a bit late because AliExpress took a long time to ship my Pixel TF-321's. They cost less than half the price we pay over here, so well worth the wait.

When you open up the TF-321, first remove the pc-sync port and the two connecting cables to create some space. No need for the pc-sync port and the hole in the enclosure later perfectly fits the wire of the ftp-splitter. The three wires you need are in the photo below. Remove the other wires, and disconnect these three from the upper side, since we are only using the underside which connects to the camera. You can see in the photo what remains after these steps.

VM-801_1.jpg

Now cut the fpt connector from an ftp-splitter, which I also got from AliExpress. You'll see the typical 8 colored RJ45 wires and an extra white one. We only need three. From opening the VS-802 and checking the connectors, I found out that Solid Blue is for Fire, Solid Orange is for Wake, White-Brown is for Ground. Cut the others short so they are out of the way. Solder the three wires to their respective counterparts in the TF-321 (again Solid Blue to Fire, Solid Orange to Wake and White-Brown to Ground). You might check the connections with a multimeter before cutting and soldering ;-)

Use the now empty pc-sync hole to lead the splitter cable through and you are done. Tested it and it worked perfectly!

VM-801_2.jpg

One of the nice things about this construction is that it fits perfectly in a vey small Peli Case (or similar). My smallest one does not have a lot of space above the camera. The regular VM-801 sits on top of a Canon-to-Nikon adapter to make it work. That won't fit, I needed a Canon TTL cable from the hotshoe, so the other end, the adapter and the VM-801 fit somewhere to the side of the camera. The thing I Frankensteined together fits in the hotshoe and only the long and thin splitter sits to the side of the camera.

That's it!