I would like to be able to have a much more granular customization of the Develop Panel. To be able to decide the order of each sliders and tools (or group of slider in case of sliders acting on the same effect like sharpening or grain). Similarly I would like to be able to customize what slider and tools go in which module, and to create or delete modules. For example, I'd like to be able to decide I want vignetting to be in its very own module, rather than with grain in the effect panel. Or I would like to be able to create a "color" module, with color balance, vibrance, saturation, HSL. Possibilities are endless.
Similarly I would like be able to place the top modules (crop, red eye, masking etc) among the other module in the scrolling pane, for example to have crop module between sharpening and transform. And to be able to "pin" any module to the top, for example pinning the curve module. Here again possibilities would be endless.
Photography has very diverse genre, and maybe it makes sense for one type of photographer to start with the white balance slider in the basic panel, but it may be more practical for a different photographer to start with cropping tool, or exposure or whatever else. True customization of the develop panel would allow every photographer to create their personal interface that fits their specific workflow.