This idea is to provide some level of drag handles to edit feature at the modeling level rather than just the sketch level.
With any luck, some clever PTC engineer can see a simple way to implement this to get splines into the 21st century in Creo.
The idea is to use the modify sliders available inside sketcher to the modeling level so that edit feature would allow selecting multiple dimensions and applying them to a slider dialog. For consistency, the same "modify" dialog from sketcher would provide consistency.
There are a lot of other improvements that should be made to splines but these things seem to get little traction within PTC. This feature is so outdated that core Creo is almost unusable for any level of industrial design. Manipulating splines today is almost a requirement in all but the most basic engineering solutions.
Please see the video to understand why this is so critical. We need to be able to manipulate sketched splines in-context, meaning modeling mode and associative to it's child features.