Thanks Scott, it makes total sense to avoid the conflict and remove the original [left] key Scintilla command 33 response. I have done that and added it to the Install summary.
For those that want to implement this Stop Left Wrap function here is a summary of the install process discussed above.
All credits to Scott-Sumner.
Version 2 - added remove original [left] move response.
Summary below applies to Notepad++ V3.3.3 (32 bit)
Stop Left Cursor Wrap to previous line:
Install Python Script Plugin
Plugins -> Plugin Manager -> Show Plugin Manager -> [Available]
Tick ‘Python Script’ and [install]
Write ‘Stop Left Wrap’ Script
Plugins -> Python Script -> New Script
Add “Stop Left Wrap” File name for Script and [Save]
This will open a new blank text file page
Copy this Python Script code to the new file and [Save]
curr_pos = editor.getCurrentPos()
if curr_pos != editor.positionFromLine(editor.lineFromPosition(curr_pos)): editor.charLeft()
if editor.getSelectionNAnchorVirtualSpace(0) > 0: editor.charLeft()
Plugins -> Python Script -> Configuration
Select ‘Stop Left Wrap’ and push [Add] to Menu Items and [OK]
Attach Shortcut to ‘left’ key
Run -> Modify Shortcut/Delete Command -> [Plugin Commands]
scroll down and click select ‘Stop Left Wrap’
select [Modify] and scroll down to Select ‘left’ key
A Conflict warning will appear. Still say [OK]
Remove Original ‘left’ key Response
Select [Scintilla Commands] tab
scroll down to Highlighted command 33 SCI_CHARLEFT and select
select [Modify] and scroll up to Select ‘none’
select [Apply] to remove original response
select [OK] conflict warning Highlight should now be gone
[Close] Should be operating now, so no more wrap on left margin.