OK, so I finally figured out what was causing my problem. In the AttachToComponent function, there is a check-box called “Weld simulated bodies”. I tried disabling that, and also turning off physics on the cubes, and NOW I’m no longer getting the collision ghosts, when I rotate the Structure. The attached blocks keep their proper line-hit detection, while they rotate, no ghosts or blocks I can’t hit.
Everything seems to be working as intended now, so I think I’ve solved my problem! 