Additional tuners for Nvidia Shield? (Who build Shield driver for Hauppauge WinTV-dualHD?)

I’m curious about buying an Nvidia Shield and turning it into a dedicated Plex server. Unfortunately, the number of available tv tuners for that device is rather - let’s say - limited at the moment.

Are there any plans to add support for additional tuners to the Shield build? Or is the SAT-IP protocol to be included in the future, so that we don’t need to actually attach a USB device to the Shield?

Why does the listed Hauppauge WinTV-dualHD tuner work at the moment, anyway? Did Hauppauge actually provide a device driver for the Shield or did someone from the Plex team actually build a driver themselves?