I want to suggest the implementation for resizable stage manager, so we can use the full resolution of the external display.
The new version 10.5.1 has completely broken the app when using an external monitor with iPad - I hope they roll back to the previous version as soon as possible.
The only thing missing with the previous version was the ability to full stretch all the way to, or select, full screen for the app on the external monitor. This was possible in some early beta releases of iPadOS16, but now seems is something for Microsoft to fix on the app side.
If a complete rollback to 10.5.0 isn’t possible then the broken features need a toggle off button in settings ASAP please - so that its possible to again use the app on either screen.