This is cool stuff! BTW, I see that you're using `avifenc` with `aomenc` to encode AVIF, so there are few suggestions that overall increase image quality per size:

- `deltaq-mode=2` or `deltaq-mode=3` each enable different flavors of variance adaptive quantization, for a more consistent image quality

- `tune=ssim` enables the SSIM tune, which correlates better with subjective quality

In addition, if you're adventurous, you might want to switch to an alternative encoder that has further tuning for static images. Examples are https://gitlab.com/damian101/aom-psy101 (which notably has a fixed `sharpness` parameter that actually works beyond a value of 1), and most recently, https://svt-av1-psy.com/avif/ with the new "still tune" 4 that reliably beats aomenc in 4:2:0 chroma mode at medium effort speeds.