Yes, you did it for the pyramid puzzle But, if you want to use it also elsewhere, no problem for me.Didn't I include the ball trap with the pyramide puzzle?
Sorry but I've lost all interest in doing something with the engineer as @GreyRoger knows best in every aspect of this game.
About the engineer's quest, it's you of course you'll decide at the end what you want and don't want to do.
People doing, in this case a quest, has the final word. You won't do something if you don't like the idea.