Have it so you can type in a command then you can click on one block on your plot and then people that are not trusted can use the block but they cant break it. For example someone can put something in a hopper but they cant break the hopper.
This would be an interesting idea, though to my knowledge no one has made a plugin like that. They would need to hire a custom plugin developer, which takes both time and money. Though it could be useful, you need to weigh the pros and cons.