The new version of the app (which handles this cleanly) is being released soon. It includes a lot of underlying changes, so it took a long while to prepare. It also includes a notification that lets you know you can clean up your downloads folders to free up disk space (that was used by previous versions of the app).
In the meantime, I still recommend just wiping the `downloads` folder yourself if you find that it gets too big.
For the curious: v25 of the app uses https://github.com/itchio/butler for all install tasks, and download folders are tracked more closely:
- Most archives are not even stored on disk, they're directly decompressed
- Same goes for patches - only windows installers need to be downloaded first to disk, then executed
- The folder for a download is wiped as soon as an install succeeds, or after it fails, if it's discarded (instead of retried).
My apologies for the amount of time it has taken - I'm really excited to release it so everyone can benefit from the improved overall reliability and performance!