App behaviour differs on non-preview from preview mode

Hello good people!

• Somehow I managed to get dev-tools in non-preview mode and noticed that our application is not embedded in an iframe but it behaves as a top-level site. However, in preview mode our app is embedded. This creates different behavior in non-preview compared to preview one. Shouldn't non-review app also be embedded?
• Is it possible to display dev-tools in non-preview mode?