Thank you for the release! I've used ECT (https://elii.cc/isdo) to losslessly optimize the PNG files to reduce the book's size by 14.6% with settings "-9 --reuse". It's not a huge difference, but you might want to think about optimizing your files this way. Here is the download: un2arx.zip.torrent
I also used cjxl (https://ouo.io/gxicYL) to losslessly convert to the new format, JPEG XL, for a whopping 49.5% savings! Settings used: -q 100 -s 9 -E 3 -I 1 htox5o.zip.torrent