It’s very sad that you can’t use AMD graphics cards…),=
I have TWO AMD R9 390 cards of 8GB each, totaling 16GB on GPUs, and I can’t run your program…),=
I suggest that you develop the option of making better use of the possibility of a 2nd video card, because with the new 4K monitors the main video cards suffer a lot from the image processing and it is important, AND MUCH CHEAPER, to have TWO video cards of the 8GB than to pay an ABSURD in “2080 Ti” to have only 12GB…),=
I ask that you INVEST in the use of CROSSFIRE and SLI technologies !!! 
And, if possible, also take advantage of our multi-threaded processors, as I have 16 threads and 32GB of RAM (64GB soon) and I would LOVE to be able to use all the capacity of my machine to render better and faster! ;^)