kAudioUnitParameterUnit_Indexed auv3 vs auv2

I'm updating a plug-in framework to support auv3 and i am noticing a discrepancy with auv2.


Previously for parameters that were stepped with whole number I would label the parameter kAudioUnitParameterUnit_Indexed. This could be used with

kAudioUnitParameterFlag_IsReadable and kAudioUnitParameterFlag_IsWritable. There were no strings provided.

With auv3 on high sierra This combination is no longer valid. If I remove the kAudioUnitParameterFlag_IsReadable Flag it passes validation or if i change the unit to custom.

Is this a bug?

Even when I get to validateIt doesn't show in garage band or logic - Which is another issue!

thanks

oli