Could I set kVTVideoEncoderSpecification_EnableLowLatencyRateControl after ​​VTCompressionSessionCreate()

Hi,

I am wondering whether I can set kVTVideoEncoderSpecification_EnableLowLatencyRateControl after VTCompressionSessionCreate()?

I meant setting it by SetVTSessionProperty( compressionSession, kVTVideoEncoderSpecification_EnableLowLatencyRateControl, kCFBooleanTrue);

And, compressionSession has been created by VTCompressionSessionCreate().

Is it necessary to set it before VTCompressionSessionCreate()?