NVENC Accelerated Codecs/Capture Software?

[ENunn]

So I usually record my gameplay through the Avermedia Live Gamer 4K and it's RECentral 4 software. It's a load of junk. I've had plenty of my videos get corrupted during some parts, and Avermedia is not helping.

Are there any other software alternatives or codecs that work with Amarec/Vdub allow support for NVENC encoding?

OBS would've been the perfect option...had it not been for the fact that I also record games from consoles that output oddball refresh rates (example: 59.83hz instead of 59.94hz). OBS doesn't really support custom frame rates for capture cards so there's a duplicate frame every 1000 frames or so. Really annoying since RECentral handles it better than OBS (even if there's a drop, it's not as bad as OBS).

I tried the good ol' ffmpeg command prompt and I cannot record at native resolution for the life of me because Avermedia can't be bothered to support common resolutions in their EDID. It's ridiculous.

ffmpeg -f dshow -rtbufsize 2048M -video_size 1600x1200 -r (59830/1000) -i video="AVerMedia HD Capture GC573 1":audio="AVerMedia HD Capture GC573 1" -c:v h264_nvenc -preset slow -qp 18 -c:a copy -f segment -segment_time 362439 -strftime 1 "F:\~ffmpeg recordings~\output\%%Y-%%m-%%d_%%H-%%M-%%S.mkv"

[dshow @ 0000025115d3f7c0] Could not set video options
video=AVerMedia HD Capture GC573 1:audio=AVerMedia HD Capture GC573 1: I/O error

Amarec works fine with native res and oddball refresh, albeit only at YUY2 max instead of 4:4:4 RGB (despite working with 4:4:4 RGB on every resolution that's "officially supported", you can't even record 720p59.94 in RGB which is ridiculous). Is there's a GPU accelerated codec that'll work with it? NVENC really helps me out. I'm not looking to record losslessly. I'm just looking for a good quality capture.