Best practice - compressing resources, or not

I have just started creating content for flathub and I have a question regarding compression of resources when creating flatpaks.

What is best, leaving them uncompressed or compress them.

In my case it’s for when creating a custom runtime image with jlink (java), the generated jmods can be compressed from zip 0 to zip 9.

I guess flatpak does some compression too…

/Patrik