Typo
In the readme, you reference scaleInstances(), but in the code this is actually scaleDescendants().

Pivot Point Support
It would be very helpful if you could add support for pivot points, so that the scaling occurs relative to the pivot point. This is also helpful since the model no longer requires a PrimaryPart, since you can just use the new GetPivot() function. Keep in mind, that you would also need to scale the Pivot Point position offset as explained here:

https://devforum.roblox.com/t/how-to-scale-the-pivot-point-of-a-model/1826773/2

Humanoid Scaling
Please add support for scaling humanoids, which is easily done through the humanoid scaling properties.

Scale Single Instance
It would be convenient to have a new function which scales a single instance. Similar to scaleDescendants(), but just for a single instance. That saves me from having to use an if-then statement to find the proper scaling method.

Thank you.