Hi there.
i'm not sure if I did this request before or if it's done by someone else but:
Open Subdivisions native support.
I'm working in a project where I need to model pretty complex technical objects and thanks to open subdiv and creases the modelling was super fast and super easy, so a native support for this with adaptativity could be very welcome and can improve the weight of the mesh depending of the camera view so we can have a visible smooth object that usually could have millions of polygons with just a few thousands polys, plus is something already implemented in several packages, max and maya for sure, about C4D i'm not sure, so native support can be cross-platform :)
Cheers!