The answer is yes. As of Studio One 3.0.1, all Softube VST3 dynamics plug-ins have support for the gain reduction meter in the Studio One 3 mixer. Making them the first 3rd-party plug-in vendor to support this custom VST3 feature. We hope that others will follow. Find out more information at the link provided here:
http://www.softube.com/index.php?id=changelog