Is there a way to temporarily block access for short periods of time while doing updates without it seeming like the app is broken?
Is there a way to have a pop up or message?
Am I going to have to do all edits at 1am?
The simplest thing to do is turn off auto publishing.
Then you can do updates at your convenience and only publish when you are ready to.
There are other things you can do like working on backups/copies and then swapping them out, or putting up maintenance screens, etc. But I’d start with turning off auto-publishing - that might be all you need to do.
No, when you turn auto-publishing off, any changes you make to the app in the builder will not be published. It doesn’t affect the ability of people to access the app.