Here is our guidance on compatibility with 3rd party devices: Compatibility With Other Hardware & Software | SimXperience® Full Motion Racing Simulator Technologies

Although it has been nearly a year since I last tried...  I usually subscribe to iRacing about one month a year to test it.  And, every time it has worked flawlessly with the Accuforce Pro V2 wheel and the NLR V3 Motion Platform [and VR]. Typically, Platform manager should be running with iRacing "Activated" [for the NLR V3] and then iRacing should be started with SimCommander [for the Accuforce Pro V2 wheel].   I have successfully used the same setup for years with older titles as well as newer titles including AC, ACC, AMS, AMS 2, rFactor 2, RRRxp, PC, PC 2, PC 3, Dirt Rally, Dirt Rally 2, FH4, FMS7, and many more games though some do require UDP forwarding [partially explained in the compatibility guide referred to above or below] from SimCommander to the Motion Platform Manager or vice versa.  If you haven't already, I also encourage you to add VR for iRacing.  As direct drive plus motion plus VR in iRacing is really well done even if the iRacing graphics and physics have felt a bit dated compared to say current iterations of ACC or AMS 2.  

One caution:  I should note that I have never used nor do I intend to use the VR Headway feature of the NLR V3 with iRacing or any other VR title.