Unable to easily adjust keyframe generation

Using go2rtc in Frigate.

I have a camera that has a 15fps stream and I have to re-encode it using h264 using #video=h264#hardware (my setup uses VAAPI). The output from ffmpeg results in a key frame every 3.33s which is too high for my uses - it's a doorbell and when I go to view the stream I would like it to load very quickly, so I was hoping to have keyframes every 1/2 second or so.

However, in all my attempts to pass in arguments to override keyframe generation results in the stream not working or ignoring the settings. I didn't want to have to re-define the entire command line uses using an exec: entry since that seems very excessive to just adjust keyframe generation, plus makes upgrading much more difficult in that I would now have to incorporate any ffmpeg adjustments myself.

I would like to know if there is a way to adjust keyframe generation when using an ffmpeg: line, and if not, I would like to suggest an improvement be considered to allow for adjust them.