Just checked, the export settings have no effect with MIDI out, only on exported data.
 
The string manager setting when exported will play a SampleTank bass on a single channel, the Channel mode will give you separate channels per string for VSTis that support MIDI guitar mode.
 
It looks like with string manager the string  selection settings are then exported to notes in the octave between C6 and C7, so either mode will work with other Amplesound basses.  These notes of course will not affect ST3 bass instruments, but may trigger spurious notes on, say a piano patch. All the pitch-bend information is exported so to the MIDI track so as long as the pitch-bend is set to the same range all is good.
 
Some keyswitches get exported in the C0 octave to select articulations, ST3 will ignore this data unless by chance it has a keyswitch in this range, or the instruments range extends into this zone.