As a Roblox developer, it is currently too hard to… scale models by a scale factor (like 50%, 200%, 32.724%, etc) for either studio or run time. I have a pretty ugly module for scaling, and when updates like ParticleEmitter and Trails came out, I needed to modify the code for it. It also still assumes the minimum part size of parts is 0.2.
The API I would like to propose is Model:Scale(ScaleFactor), which would allow for scaling by a certain factor for a given object, while being future proof to new objects or changes to the minimum size. Two use cases would be for developers who build a small model 10x bigger than they need and properly scale down, and scaling objects down ingame to adorn to a position on the screen without clipping easily into the ground.