My suggestion is allowing you to specify custom parameter types for property setters
Example:
var value: MutableFloat
set(val: Float) { field = field.apply{setFloat(val)} }
This prevents having to create a function setValue(4f)
and instead allows you to do value = 4f
This would reduce a lot of the boiler plate from wrapper classes.
I understand this could create confusion about the variable type, however the developer should use it responsibly.