Another quirk is that the editor sometimes seems "sticky". Sometimes I cannot backspace at the end of a word. I have to move the cursor elsewhere and reposition it where I need it (or somewhere close by) in order to get backspace to move again. I also cannot erase smilies using backspace (usually right after I have inserted them from the menu bar).
Also, when medium-pressing in the editor (longer than a tap, but shorter than the interval to activate text selection), this should activate a "Paste" button at the spot in the text where you want the text to appear. The appearance of the button is erratic. Sometimes it appears, but disappears when you lift your finger. Others, it has difficulty appearing. In other web forms and some apps, it works properly.
I am seeing the issue here as well as on my test forum running the latest release candidate.
Nothing critical here, but just wanted to bring it to your attention for a current or future fix.