Among the many Radio News articles recently added to the ETF site is one from December, 1928 called
Television Makes the Radio Drama Possible. I think they got that backwards, but that's the title.
Anyway, it turns out to be an article about GE's broadcast of The Queens Messenger over WGY and goes into great detail about both staging and technical aspects. What may come as a surprise is definite and repeated references to using 24-line apparatus. This confirms what I had long suspected but had been told was not the case. Apparently they had no choice due to restriction to a 5kHz broadcast bandwidth. The same article later talks about the 48-line standard being developed for projection use.
It really makes sense when you think about it. While 48 lines is still acutely lacking in detail, it would have been sufficient to stage the two actors at a table manipulating their own props. Only at 24 lines would such extreme closeups be necessary.