NAD83 2011 / ITRF2008 conversion to State Plane

Discussion created by cdixon on Jul 31, 2013
We have incoming data in ITRF2008 that we are converting to NAD83 2011 through an outside API.  Our customer would like state plane, specifically North Central Texas 4202 FIPS Feet.  How can I do this?  My understanding is neither of these spatial references are supported yet with SpatialReference.  When I use GeometryEngine.project(x,y,SpatialReference.create(wkid)), our values are off by 2 feet with NAD83 and around .9 feet with ITRF2008.  I'm sure this is because this function expects WGS-84.  Is there a way to create a custom spatial reference, or some other workflow I can do to accomplish this?