In my opinion, the generic pipe supports that come with Plant 3D fall short of what is needed out of the box. I had the same issue with the alignment guide. It would be nice if Autodesk would update the pipe supports that come with Plant 3D. I have used the 3d models from Anvil to create more realistic pipe supports. There are several companies that have parametric pipe supports for Plant 3D. I suggest that you check out the Youtube by Scott Hallmark that gives some great examples. I met Scott at AU in 2014. Here is the link to the video. You will have to restart the video.
https://www.youtube.com/watch?v=yMpcfomJdI8
