All in all, it's still a strange omission in an otherwise powerful instrument. Would the Wing be classed as a TOTL or MOTL arranger?
I have taught quite a few people to edit and assemble Yamaha styles, both on-line and in my clinics, and it's surprising how many realize just how simple it is once you see it done, or it's explained in a simpler way than most owner's manuals present it.
Of course, there still will be those who only buy or borrow styles, and ready made song-specific styles are very popular.
Yamaha's Premium styles are often a great starting point for making newly edited styles, and the styles on the more recent Tyros will even allow have organ parts in a style to have realistic speed up/slow down Leslie. That sounds really cool.
Even simple style re-voicing, changing effects, and even volume adjustments can make a dramatic difference in a style.
I'm betting the Wing will at least let you do those operations on board.
Price wise it is in-between MOTL & TOTL models, so to be quite honest I am not quite sure what to call it, plus as it’s the only one they make can it have a designated position?
As for editing like you mentioned, then since the June 2012 update Yes, however when it was officially launched in March/April 2012 it couldn’t. (It was soon fixed though)
Here are the updates so far:
V1 R 00:01 - 00:02 (May 2012)
New options for saving of Total pre-sets
Way to display karaoke lyrics
Additional settings Sequence Transpose and MIDI multimode
Correction of the foot switch control
V1 R 00:02 - 00:03 (May 2012)
Expansion of Footswitch settings and some corrections
New Drawbar tone module VB3 Wersi Edition
Full display of tone module settings, plus saving of tone module settings
New optional sound package "Best of Accordions" for the Pegasus Wing
Error messages eliminated after restoring the factory settings / loading a backup
V1 R 00:03 - 00:04 (June 2012)
Enhanced MIDI Editor
Advanced Style Editor
15 new Drawbar tones added (level 7-9)
New optional sound/style package "James Last Edition" for the Pegasus Wing
Eliminates error messages after restoring the factory settings / loading a backup
V 1 R 00.04 - V 2.0 R 00.01 (August 2012)
All Styles has been adjusted in volume
50 new Live pre-sets by Robert Bartha
New optional Sound/Style package "Franz Lambert Edition" for the Pegasus Wing
New optional sound package "Portamento sounds" for the Pegasus Wing
V 2 R 00:01 - 00:02 (October 2012)
50 new song pre-sets by Claudia Hirschfeld
New optional extension "Selector Plus" for the Pegasus Wing
V 2 R 00:02 - 00:03 (November 2013)
45 new pre-sets from music store employees
New optional Style Package "MS Professional Style Edition 1"
New optional Style Package "Modern Pop-Rock Style"
New optional Style Package "Schlager-style package 1"
Harmony Quantizing for the auto accompaniment
Foot switch assignment - Global Setting
Bug fix: foot switch assignment - corrected caption
bug fix: VB3 - tracking the expression pedal the sound now changes correctly
Bug fix: When importing pre-sets the name is applied correctly
Bug fix: After deleting a record, instrument no longer has to be re-started to show new slot
NOTE: the above has been translated from the German manual so may not be 100% correct.