General App prod vs dev

So I created a General App under my Zoom account. The purpose for this is so that in our internal system, the user can join a Zoom app via an embedded client in the webpage.

My app is in “draft” mode. I don’t really need to push it to the marketplace. I notice that I can join meetings with the develpment keys, but with the production keys I get a “Invalid Signature” error.

Is this expected behavior because I haven’t published my app?
Do I really need to publish my app or can I continue using the development keys forever.

Any guidance is appreciated