Thanks for your response!
I understand that it is possible to have low res images by default and by creating a manual lazy load of separate new higher quality images and replace the spriteFrames.
The problem is that you need in this case to keep duplicated assets in your project of every asset you have and replace them all in an manual way.
I’m looking for a solution where you have one high res version of the image that then during the build process would create one a low resolution and highly compressed image that would be used as the first images loaded and then another high res/quality image that automatically then gets replaced.
Duplicated manual work of assets of every spriteframe in a big project would just be a mess