As a mobile player. I find it hard trying to turn my camera and not trying to destroy my wheeled vehicle at the same time. Because even when I don't mean it, I punch. So my idea? Simple! Since there's already a destroy tool, we can instantly destroy a certain part! So my idea is that if an engineer (accidentally) punches a part of their contraption, it won't take damage! Instead, you can repair that part.
Another idea. I don't really know why there's a checkmark since I can't even use it, so let's make the engineer settings a bit more like Build a boat for treasure! The checkmark button places the block! And you can scroll down and up to find a certain something!
If this idea isn't something, I apologize. As it's what I experience.