When X2  names soft synth inserts, it appears to only look at the previous table
 entry to avoid duplication. So, if you add a half dozen Kontakt instances, they
show up as 1,2,3,4,5,6. So then you add Play or Engine or SWAM or whatever, and
it starts over with numbers. If you then add more instances of Kontakt, it
starts over at 1,2,3, etc., and duplicates the names and you end up with multiple
instances of Kontakt 5 1 for example, and that seems to create a problem. I know
its possible each synth table entry might have a unique index that we don't see,
but I usually get these duplicate name synths stepping on each other until I go
back, rename everything, close, reopen. It would be helpful if SONAR could check
new inserts and avoid the duplication. Or I could just go make another big ass template.

It would be nice to allow "friendly" names when the insert synth dialog comes up.

I rename them to the instruments. For example, I might change the Kontakt instances to Electri6ity (or Strat or 335 or Les Paul), Acoustic Legends, Mandolin, etc.  Play would become Hollywood Strings, FabFour, etc.  Vienna Pro Player would be 1st Violins, 2nd Violins, Horn, etc.
 
It would be nice to name them when you open the synth, but you can click on them and change them.  Hint:  While the text editor is open on the soft synth, I copy the text so I can paste it in as the track name.

I always rename the Kontakt outputs to realistic instrument names, and it makes the routing for the audio tracks easy.
 
I would like to have better naming options for the synths, though.
 
Bob Bone
 

I always add synths via the Synth Rack, and immediately rename them there. I'm likely to have 20 or 30 synth/sampler instances in a project, so it's more helpful to me if the synth has a name like "Sax Solo, Verse 3 (Kontakt)" or "Intro Pad (Zebra)".