I finally got myself an M2 iPad Pro so I could add support for Stage Manager on external displays to Textastic.
The photo shows Textastic's code editor, a separate file transfer window and a Safari window for web preview on the external display, and an SSH terminal and another editor window on the iPad Pro's display. All working at the same time.
Try it out for yourself with Textastic's just-released version 9.9.2.
https://apps.apple.com/us/app/textastic-code-editor/id1049254261

