Great! For the technical scope of what I'm building, rolling my own engine hasn't been a hindrance and having full control makes it a much more engaging project for me.

The design constraint that is proving more difficult than I expected is that most of the game needs to be defined in editor assets, with the goal being that anybody could do mods or overhauls from the asset database. Everything needing to be an asset is a very exciting challenge but it has made some parts of the engine development very difficult!