I concur, both options help a lot. I noticed that the ffmpeg packages are sometimes a bit outdated, yielding a gigantic gap between what the stock ffmpeg can do, and what a freshly compiled one does.
Also, having more cores helps a lot with SVT-AV1.
See also the documentation. [1]
[1] https://github.com/AOMediaCodec/SVT-AV1/blob/v1.0.0/Docs/Ffm...
ffmpeg -i input.mp4 -c:a copy -c:v libsvtav1 -crf 17 svtav1_test.mp4
Hopefully using the SVT-AV1 encoder helps speed up your encoding.
[1]: https://trac.ffmpeg.org/wiki/Encode/AV1