I think it would be a very useful feature to allow each of the individual dynamics sections in ProEQ (when using it as a dynamic EQ) as well as Multiband dynamics to have individual sidechain inputs. This would allow either of those processors to offer some very unique routing possibilties.
For instance- in the case of a keyboard driven song, you could place a single ProEQ on the keyboard, and have a single dynamic EQ band processer side chained to a vocal track and have that single band set at 1K to duck the keyboard when the vocal happens, and have a second dynamic EQ band processor side chained to the bass guitar track and set to 300hz to duck the keyboard when the bass happens. This can already be done by using multiple instances of ProEQ on the track and sidechaining each one independently, but this method would be a lot more convenient and CPU friendly.
I believe this feature is available in Cubase 11+ (can't verify that) but short of that, I know of no other DAW that can do this, and I think it would put Studio One ahead of the curve.
Thanks!