I have it and got it working. The dual ThunderboltEX II is available on Amazon through a trusted retailer (I got mine like 5 days after I ordered). They go fast fast though, I was lucky to get one. They're only $10 more than the single port too. Security must be turned off in BIOS (legacy in UEFI BIOS>ADVANCED>THUNDERBOLT) for it to work BUT...
There's a problem under SMBios6,1. I can't get passed PCI Config in -v if I have a TB Device plugged in. With the actual PCI card installed 6,1 boots fine but no PCI Thunderbolt device is found in the IOReg tree. The only solution I could come up with is just using 5,1 and after deleting AppleThunderboltNHI.kext (solution was found here under TB testing thread). If you don't remove AppleThunderboltNHI it boots super slow and is kinda buggy (my keyboard wouldn't be found for 1-2 minutes after boot for instance). But under 5,1 everything works great, minus the advantages to 6,1 services. I have a friend who knows a TON more than me working on the 6,1 issue and hopefully he can resolve it. So long story short: yes, it works!
Now I have a 4.5Ghz (78°C under torture) EIGHT Core, 32Gb 2666(evil) DDR4, 2x Titan Black AND THUNDERBOLT 2 Equipped Hack. It's a good time for Hackintosh (minus X99 power management - which WILL come soon).