That's right but there aren't other inbuilt features with them you could adjust these properties.
If you have only a few varieties you could create an single object for each and control then the visibility of them. But with many varities it's not very practicable. The only way then would be to use an extension for it. I think if you searched for extensions you will find any examples which have implemented a way to control the heights and widths and which you could then adapt for your solution.