Hi BocaBoy,
It sounds like you're wondering if MagSafe supports landscape screen rotation. We're glad you've joined us in Apple Support Communities. Let's see if this helps.
Many apps support screen rotation, but not all do. That would depend on the app. The link Change or lock the screen orientation on iPhone provides similar information.
Let's perform a quick test. When connected to MagSafe and you open the native Mail app does the screen rotate to landscape? We ask you to try this because it should rotate. If it doesn't rotate, double-check the steps in the link above to double-check that the lock is off. If the issue continues, have you had a chance to restart and check your iPhone for updates? Both restarts and updates resolve issues both big and small.
If the issue seems to be with some apps and not others, then this is by design by the app developer. We understand that the app normally rotates to landscape fine without being connected to MagSafe. So in that case, you'll want to make sure the app is up-to-date with the advice in, How to manually update apps on your Apple device. Oftentimes, when the iOS version gets updates, so do apps.
If you've checked out everything from the above links and are still wondering what to do, you'll want to reach out to the app developer. How to contact an app developer will tell you how. Keep in mind, it's up to each App developer if they support (have coded that to work in their app.)
We hope that helps with your question and take care!