Hello William! I agree that this insert dialog could be larger and so I've added my upvote here. I am not sure if this is something we can adjust from our end, but we can certainly look into it for you. 

Thank you Kyle, much appreciated.  It's likely just a CSS override that you'd need.

I was able to speak with development on this and they've advised me we will need to research this further. With that being said, we are not sure we can adjust this since it does stem from the Froala editor itself. In the meantime though, you can use the Insert Code functionality to generate the code block, then click into that section of the response where you can edit it realtime without the tiny dialog window. I did get this on our list to look at in the future though. Have a good one!