"Personae"-----The volume I used is the one edited by Baechler and Litz published in 1990 by New Directions

I believe, although I cannot be certain, that the spaces were inserted by Pound after the first publication.

Referencing your concern about the typesetters, Pound apparently did not have those concerns or at least trusted himself as a final proof reader.  A casual look at "The Cantos" shows that Pound used word spacing and line spacing throughout his work.

Rick Seddon
Portales, NM