We currently don't have cuda support, we rely exclusively on ffmpeg and as you have noticed the version we use is from before this was available at the ffmpeg side.
We have made some experiments with the other hw accelerations that were available such as DXVA2 and unfortunately the results weren't really impressive.
The main problem / limitation is that we work with RGB32 pictures for the overlay, for the motion detection, for generating the live jpegs etc... so somehow what we gain by use hw accel is being lost by having to 1) transfer images from the GPU to the CPU 2) converting the images back and forth to RGB32.
This whole hw acceleration is generally tricky and quite complex to put in place, we already struggled a lot to get the existing modes to work (despite they don't provide much improvements against pure CPU mode).
I will check with my ffmpeg expert which helped me to put in place if there's any interest into looking again at CUDA now that it's in ffmpeg but I doubt it's something that will be available on our end at short or mid term.