I have been teaching and using the hack to use railing supports in leiu of baluster or to use them for gates etc. Yesterday a client told be about an issue with Railing Supports, they do not abide by phasing graphic overrides. In cases where the supports are simple brackets (as shown below this probably isn’t that big of a deal.
However when you are utilizing support for balusters or for gates (as shown in the two images below) this becomes a big issue. This has been reported to Autodesk and I was able to reproduce the issue in both Revit 2017 & 2016, I didn’t test it in older versions of Revit.