IPad extended monitor

You are very welcome.

Stage Manager has been in development since it was announced at WWDC22 in June. Late in the beta lifecycle, support for Stage Manager was extended to include other models - and external display support was removed from the late beta releases; presumably the feature would not be ready in time for the first production release of iPadOS15 for iPad.

Apple’s current feature article definitely says this feature is coming…

iPadOS 16 - Apple

Presumably you refer to iPadOS16 Stage Manager support for external monitors. Apple have not published a specific date - only that it will be available “later this year”.