Why do RML-series rack-mount mixers not have compressor with sidechain?

Hi,
We use RML32AI rack-mount mixer on the stage but the problem is that there is no compressor with sidechain whereas StudioLive Series III mixers have this amazing feature. Before we bought RML32AI mixer, we had watched and read that new features would be added in time. According to your videos, we have been waiting for this feature via new uptade. After we saw that StudioLive Series III mixers have this feature, we believe it is a significant feature that should be added on RML-series rack-mount mixers via new update. 

We are looking forward to your reply.
Thanks in advance!