I have found one thing that helps me if I need to comment by iPad - my preference is still to do comments on the proper keyboard.
Since this might help others, the tip is to use the Keyboard shortcuts on your iPad. You set them up by going into Settings - the icon for this looks like this:
Then scroll down til you find a heading Keyboard (it's between Date & Time and International) - touch that line and you will see the heading Shortcuts. And a line "Add New shortcut".
If you push that you can put in a phrase that you commonly use when commenting - like say - have a great day! And then you put a shortcut for that in - like hag. And then push the blue Save button
Then every time you type hag the phrase Have a great day! will pop up and you just confirm it by pressing return on the keyboard.
One warning - don't make your shortcut a word that you will use in other contexts! If you do, you will soon find out that your phrase pops up when you don't want it!