I know, I miswrote. I was compressing the images within the rpa to webp and I got down to 180 mb and then compressing the rpa again.^ The rpa is already compressed, that's why it takes a few days everytime you start the game, it needs to decrypt and extract all that junk then load it to RAM
The problem is that SummerTimeSaga uses transparency so webp images don't work. Wanted to compress the png to png (yes, possible)
But then I saw it's already compressed to less than 400 mb. I hadn't noticed