Following up on Greybeard’s comments:
Yes, you can connect an iPad Air Gen 4 to an external monitor that supports Thunderbolt, HDMI or Displayport. No, the Air doesn’t support Stage Manager.
Ok excellent, so this should work for someone like me who simply wants a larger screen when working with apps, such as GarageBand, Procreate, or other photo/video editing apps? I have a 24" WQHD Lenovo monitor that has usb-c (connects and charges my MacBook Pro). I don't really care about Stage Manager; I guess that's what Apple's M1 limitation means in iOS 16. Are there any drawbacks visually to this approach? Are there scaling issues, etc?