I downloaded this on my tablet, I'll be checking out if this can work on my Windows ME system tomorrow as I've only partial read support for this format on that system and none for encoding. I can read some flavors of it in XnView via a susie plugin and an old version of Image Magick and others with Gpac, and yet some other with nothing.
BTW, with regards to png decoding, compression levels have to to do with file size vs speed not quality, png is always lossless.
Heic, avif and jxl beat old formats quite massively with regards to filesize for identical quality but are all damn slow, about 100x slower to decode in a few tests I made, so nothing I am going to adopt for my own use, especially as storage space is not issue anymore these days. Nice to have decoding options for these formats though.