We could set the height on the control, but we really wanted to make it user adjustable, which sounds like it is what you are working on yourself.
Not with this control, we have different needs.
If the answer is that to do exactly what we want, I would have to modify the StrataFrame source code, then that's what the answer is and we can evaluate if it is worth putting my time into from there. I've been a C/C++ and now C# developer for a long time and I've written many custom controls in the past, so I know it is doable - the real question at this point is, is it worth the time.
You have the source, but it is in VB. But if you want to copy this code and re-write the control to meet your needs then go for it. This way you are not changing the SF code so you can just load updates in the future. In truth, you may be able to just inherit this control and then override the OnMouseMove and add your logic for resizing. This way it is encapsulated. This would be the road I would go down first.
On the other hand, if you are doing the exact same thing and wouldn't mind sharing it, it would be appreciated, but it is understandable, if you cannot.
The control in which I am referring is not the same as this control. It is far more involved and has the ability to add links to a header, etc. It is a container control like the ThemedContainer, but it serves a slightly different purpose. As mentioned, though, once put through the trials and tests, it will most likely make it into the framework. But for now it is a ways out of being ready for multi-purpose distribution.