"In March 2017, CIG announced Star Citizen would eventually use the Vulkan API and drop support for the DirectX 12 API to support Linux and pre-Windows 10 users."

Changing graphics APIs six years in...  This is what happens when a noob with a dream hits it big with a kickstarter campaign. Anyone who has done this before knows fundamentals like whose tech they're going to use and why before they even start talking to others about it.

They're still probably lost. Vulkan 32 bit doesn't work, so unless you are consciously leaving 32-bit platforms behind or actually need a multithreaded graphics API (you don't, and if you do you're doing it wrong) OpenGL is still the way to go for multiplatform games like this.