I ran several tests with this workflow; here are my results:
Cursor 'Left' with prefix [space]: [space] is prefixed to selection; on re-editing the hotkey, no [space] is found in 'Prefix' area Cursor 'Right' with prefix [space]: no [space] is prefixed to selection; raw selection returned; on re-editing hotkey, no [space] is found in 'Prefix' area Cursor 'Left' with prefix 'a': [space] and 'a' are prefixed to selection Cursor 'Right' with prefix 'a': 'a' is prefixed to selection; functions normally
It seems that setting the Cursor to 'Left' automatically prefixes a space; this should be option