There’s been some discussion of this in the past — that said, I worry about the USB subsystem on a machine and it managing that many device connections (probably baseless, but this isn’t a configuration which would get much testing).
My inclination would be to suggest that you contact Carbide 3D sales/support and see if the “Carbide Connect” board which they announced would be a good fit — no idea on when it’ll be ready for deployment, but headless operation on a machine is really nice. (I miss it from my 3D printer w/ Smoothieboard and Viki 2 LCD / wheel when using my Nomad or Shapeoko)
EDIT: announcement was here: http://carbide3d.com/blog/2017/state-of-carbide-3d-2017/