I think Huw charged from edition 5 onwards.
I wonder how much extra you get, that would make it worth the expenditure?
You can design without engineering, but you cannot engineer without design.
Using Win 10 with Designer 2017-2020 and TurboCAD Pro. Plat. 2018-2020 + Lightworks (64-bit versions) + AnimationLab 5.2.
Windows 10 Pro (1909) 64-bit