That patch is manually added. Moreover, some apps have hard binding with their id, making the situation more complicated. Kiwi is not on f-droid at all. They host their own version. It might be easier for the app authors to do it. But f-droid maintainers don’t have this capacity.

The thing is that changing the app id requires too much patching to thousands of apps, and the users will not be able to migrate from the current f-droid version.

Good to know that they have first-class Linux support.