We haven't specifically compared to AVIF, which as far as we know is still under development. We'd be happy to compare, but it's unlikely that we'd learn much out of it. As far as we know, AVIF is better by <100% than HEVC, but we're comparing against HEVC at 300% of the bitrate.
Of course, we'd be happy to add any additional images from other codecs if they're available.
I would add JPEG-XL in addition if you're looking for suggestions for other codecs to compare to. It's very competitive with AV1 and beats it, in my opinion, at higher bitrates.
Admittedly, you're not likely to learn much from this that is useful for your research, but most of the interest from people clicking on this is probably wanting to see the latest developments in image compression.
Of course, we'd be happy to add any additional images from other codecs if they're available.