As I understand it (I’m not a string player), this means that the rising notes from the G are to be played on the A string and the 3 Es are natural harmonics on the E string. Ideally I would like correct playback but I would settle for just correct notation that would be understood by a violinist.
I’d also recommend using the contemporary “0” indication for the open string, rather than the “o” used in your example.
and this, for the exact reason pointed out here: those Es are not harmonics, they are open strings (zeros indicate “no finger”.)
So use Dorico’s fingering feature to notate them as such, rather than the harmonic circles.
as far as I’m concerned, even the “sul la” is redundant, since it’s obvious what needs to be played here.
to get the separate up/down stem notes, just write them in two voices: the Es in voice 1, the G - Bb in voice 2.
yes, that’s a two-octave harmonic on the A string for the contrabass (touch 4th.)
this is one of the main reasons for NOT using the small circle to indicate an open string. there’s simply too much confusion between a harmonic and an open string fingering.
this is a particular problem when examining hand-written scores.
here’s an example from my violin concerto. notice that I don’t bother with the “0” fingering the 2nd time the figure repeats. It’s self-evident.
bar 73 is simply a double stop,
bar 74 is a single harmonic,
bar 75 is the double stop with crossed voices, as in your example,
bar 76 is back to a single harmonic,
bar 77 repeats the crossed voices, but no fingering, since it’s self-evident due to the previous instance of the motif,
and bar 78 is a slightly mean chromatic shift into an artificial harmonic.