Doesn't this make it prohibitively difficult to do local builds of open source projects? It's been a long time since I've done this, but my recollection was that the process to do this was essentially you would build someone else's (the project's) package/namespace up through signing, but sign it locally with your own dev keys. A glance at the docs they've shared makes it sound like the package name essentially gets bound to an identity and you then can't sign it with another key. Am a I misremembering and/or has something changed in this process? Am I missing something?