Just for the devs: This is a major stumbling block to new users.
It's easy to make an Art Text box instead of a Text Frame because they both use the same keyboard shortcut, `t` (same as InDesign's text box).
The signifiers that differentiate the Artistic Text and Frame Text tools aren't strong enough. Same goes for the layer icons. Compare the Artistic Text 'A' to Microsoft Word's WordArt icon. Now that's differentiated!
The only thing that differentiates the boxes on the page is a single dot.
The two behave the same until you try to resize them.
If you use the wrong one, the only way to fix it is to remake it. There's no conversion tool.
I just made masters, precise layouts (Bringhurst's golden section grid on ISO), running headings, page numbers, sections, table of contents, and columns for a 46-page prospectus only to find out (once I started putting in real content) that I used the wrong kind of text box. This is not the kind of initial experience you want users to have.
It'd be good for everyone if there were an easy way to convert Art Text boxes to Frame Text boxes.