Trisquel does include packages not in the standard Ubuntu repos all the time.
It's just that I got an Nvidia GTX 970 recently and having later kernels actually let's me boot with it connected without using Ubuntu with the non-free drivers.
The 3.19 kernel, when its released, will support the chipset better and so will Noveau.
I suppose the other option is to run a netinstall and use the external repo to get the kernel before I install a desktop environment.
