Yup, I know about the limitations. I haven't found it necessary to hack the driver. Of course I've been waiting for a bargain P2000 to come along but after a couple of years, they're still expensive and hard to come by.
Anyway, both the Intel Iris Pro Graphics P6300 (IGPU) and the dedicated 1050Ti, together with the CPU, do pitch in to do the transcodes. That said, Nvidia's 2-stream limit is not too big of an issue for me. At least, not yet.
CPU, GPU 0, and GPU 1 utilization while plying 4 or 5 streams:
