In the simple two-staff examples, i'd use the model of Example 27-25-1, using intervals for the notes in the hand parts. Look at that example, omitting the alternative line of analysis. That way, the notes remain aligned with the associated bass figures. Whenever it gets more complicated, involving even one in-accord, I'd use Example 27-23.1-1, in open score. I think absolute clarity for the reader takes precedence over saving space. It is very likely that the reader will be assembling the music in his head, without actually playing it on an instrument, just as a sighted reader probably does. In fact, reading figured-bass, he might actually be reading chord-by-chord. It might be a stumbling-block not to have the chords and their abstract symbols in alignment.