I've noticed that some of the symbols don't swap with space the same way the comma & period do. Some symbol I would like to recommend be added are the end brackets. The ) and ] and } should be added.
If you type (like this ) or [this ], there is a space after the last word, unless you backspace first.
Also, I noticed that you can't put a period after the brackets when you double tap the space bar or select + space. Sometimes, something in brackets will occur at the end of a sentence.