In mkv with hevc_nvenc and a Quality-based VBR. Changing preset=p1 to preset=p7 has no effect, and changing tune=ull to tune=hq also has no effect. Probably not a huge deal on the tune, since I assume it’s defaulting to hq anyways. Also, the encoder option bufsize does work, but it won’t save to a preset. It is removed after saving.