It’s available in the Izzy on droid repo, you’ll have to add the repo to the f-droid app with the following URL:

https://apt.izzysoft.de/fdroid/repo?fingerprint=3BF0D6ABFEAE2F401707B6D966BE743BF0EEE49C2561B9BA39073711F628937A

Or scan the QR code here: https://apt.izzysoft.de/fdroid/

That’s fair

If you wanted to try to make your original rubber band idea work, you could try moving the central dart up slightly so that the rubber band forms a triangle shape and adjust the contact points between the rubber band and the darts to be at each corner of that triangle

If you’re using BTRFS and know how to/are prepared to learn, just create separate sub volumes instead of multiple partitions. Means that you don’t need to decide how to split up space between different partitions and they are easy to delete without a live USB.