Currently, when rotating an object in a layer, the object scales down then back up within the rotation:
Any way to change it so the object stays the correct size?
No. the layer records not a rotation, it records a shifting of vertex positions from start to end position. There is no workaround for a animation of a rotation via layers.
I know, currently there’s not. So that’s why I’m requesting it 
Sorry, I overlooked the feature request.
No worries!
I know a lot of people use layers so maybe there’s a workaround for something like this:
When rotating an object on a layer and then sculpting on it, once you use the layer function to see the difference or make an angle change, the size of the object changes.
This makes it so that if you need to change the angle of an object then you have to now scale it or re-sculpt on the object to get it back to the correct size. So having it rotate without a change of size would be nice.