I think it is possible to blend the tensorrt version of RIFE into svp, you can write the code in c++ and generate dll for SVP to load. The additional dll dependencies required (cuda, cudnn and tensorrt, about 2GB without compression) can be placed directly in a folder without letting customers download and install them from Nvidia. Use tensorrt and enable fp16 indeed can boost FPS greatly(INT8 quantization is even faster, but will influence the performance, while FP16 just shows minor effects). Though generating .engine file can cost some time, but once the .engine file is generated, there is no need to generate again, so I don't think it is a problem.
The future of real time interpolation for video definitely belongs to AI(maybe everything in computer vision).