Some plugins have an auto-gain control to keep the volume of the signal stable. As example, when you decrease 6db to an eq band, the plugin automatically calculates how many db increase the output volume.
This is a very useful feauture for mixing, and specially to take care of our ears, avoiding big increases of volume that can damage the tympanic membrane.
A lot of plugins don’t have this feature. That’s the reason I think it could be great to have an auto-gain control in the header of the plugin window, near to bypass button.
Auto-gain control could be a button kind “on/off” like bypass. Another additional feature could be a drop-down menu to select how gain-control must work: change output volume in db or in loudness.
This feature could be added also in Preferences with a checkbox saying “Always open plugins with auto-gain control enabled”
It would be necessary another configuration option: select wich plugins are “forbidden” for auto-gain. As an example, Fabfilter Pro-Q has the auto-gain feature inside the plugin, so it will never be necessary use Cubase auto-gain control in the header of the plugin window. So I would check Fabfilter Pro-Q as a “forbidden” plugin for auto-gain.
This configuration could be done easily in the plugins manager window.