I dont know why but the onboard keyboard is so big you cant see anything and you cant kill the app either, you end up having to log out the session and log in again.
whoa xD
Try to looong click on the return visual key, it will prompt you a menu to open onboard settings 
:
Once there, you will be able to resize the window. If you do not see the window, you can close the visual keyboard using once again the same way; long click on return next the close icon.
Thanks a lot for this, I managed to get to settings but the keyboard still looks too big, despite me changing size settings.
You also taught me how to post a video onto a site like this by way of turning it into a moving gif so thanks for that too.
I'm using peek to create animated screenshots
Nice peace of software for a administrator that need to provide evidences of his work on daily basis xD
Maybe try like this :
The icon on the meddle allow you to move the keyboard that can be helpful if you don't see the resize icons.
hahaha, this keyboard simply do not want to work xD
Maybe try to reset all the configuration of the software
You can do it removing all it's settings with dconf-editor :
I would give a try exiting onboard and next removing all this key :
i've uninstalled it, rebooted, then reinstalled it and I ran it to get the same issue. Furthermore, upon changing a setting I can see the keyboard starts up in the right size, however, you can also see giant keyboard letters behind it. Then when I go to click on a key it goes back to original problem of it being too big. Any other onboard keyboards out there? I am starting to feel like I wasted too much time on this issue.
Try to remove this key inside dconf-editor, maybe it will help
I was using UM on a lenovo miix 320 and gave a try to some of them. Onboard is far in front the best of them all.