VIU is dedicated on identifying controller model for connected controller device
VRModule.GetDeviceState(ViveRole.GetDeviceIndex(HandRole.RightHand)).deviceModel
This property should tell you which device is currently used
public enum VRModuleDeviceModel
{
// ...
OculusTouchLeft, // Oculus 1
OculusTouchRight, // Oculus 1
// ...
ViveFocusChirp, // Focus Plus
// ...
OculusQuestOrRiftSControllerLeft, // Oculus 2
OculusQuestOrRiftSControllerRight, // Oculus 2
// ...
WaveCRControllerLeft, // Focus 3
WaveCRControllerRight, // Focus 3
// ...
}
(This maybe a good point that we may consider adding more HMD device model but only if there is a strong reason or strong request, in case you need to know the using device without any connected controller)