Consider distributing ZIP files containing the game directory rather than installers, so that the game can be downloaded through the Itch app. You can still distribute installers as well, just leave the OS tag blank so Itch doesn't try to download the installer through the app.
Viewing post in Zero-K is ready for itch.io comments
If you're hitting some kind of limit you can open an issue here https://github.com/itchio/itch/issues