videoTemporalSpatialTradeOff in Multipoint with centralized video

Hi All:

I have a question about some H.323 MCU operation in a multipoint conference with centralized video. When the MCU switches from one video to another, does the videoTemporalSpatialTradeOff indication need to be sent? In H.245, it is stated that the videoTemporalSpatialTradeOff indication needs to be sent only when a new LC is opened or the encoder changes it.

Thanks, Samson