If you are just looking to create a display prototype (without long-term maintenance concerns) then another option would be to copy the entire TIECropToolInteraction class to a local unit, rename the class and then add it to TImageEnView.UserInteractions:
fMyCropToolInteraction := TMyCropToolInteraction.Create(ImageEnView1);
ImageEnView1.UserInteractions.Add( fMyCropToolInteraction );
fMyCropToolInteraction.Enabled := true;
That way you could manipulate the functionality and styling of the crop UI as much as you need.