I’d like to add that non-uniform scaling inside PreForm makes sense because because distortions happen based on print orientation (and other parameters – in my case thin-walled parts are very sensitive to this), so they logically belong in the print file, and I don’t buy the complication argument, as the interface is already there, all that’s needed is a little lock symbol where the current input fields are.
What would be a useful addition is scaling in model coordinates as well as “global” coordinates, as the the non-uniform scaling is mostly aligned with geometric features and their shrinkage, eg. a non-axis-aligned thin-walled cylinder is very likely to shrink in circumference, but not length.